Judge KATZMANN concurs with a separate opinion.
[555]*555RAGGI, Circuit Judge.
Petitioner-Appellant Thomas Dallio is a New York State prisoner, serving a term of twenty-two years to life imprisonment as a result of his November 13, 1995 guilty plea to two counts of murder in the second degree, one for intentional murder, N.Y. Penal Law § 125.25[1], and one for felony murder, N.Y. Penal Law § 125.25[8]; one count of robbery in the first degree, N.Y. Penal Law § 160.15[2]; and one count of criminal weapon possession in the second degree, N.Y. Penal Law § 265.03. Dallio appeals from the November 1, 2001 judgment of the United States District Court for the Eastern District of New York (Frederick Block, Judge) denying his petition for a writ of habeas corpus filed pursuant to 28 U.S.C. § 2254. See Dallio v. Spitzer, 170 F.Supp.2d 327 (E.D.N.Y.2001).
In his petition, Dallio asserted that his Sixth Amendment right to counsel was violated at a pre-trial suppression hearing when the trial court permitted him to proceed pro se without first giving him explicit warnings about the “dangers and disadvantages” of self-representation as required by Faretta v. California, 422 U.S. 806, 835, 95 S.Ct. 2525, 45 L.Ed.2d 562 (1975). The district court agreed that the lack of such warnings violated the Sixth Amendment but concluded that the error was harmless. Dallio v. Spitzer, 170 F.Supp.2d at 336-38. We affirm the district court’s judgment without reaching the question of harmless error. See Boule v. Hutton, 328 F.3d 84, 92 (2d Cir.2003) (noting our ability to affirm a judgment on any ground appearing in the record, whether or not relied on by the district court). Although explicit warnings as to the dangers and disadvantages of self-representation are certainly advisable to ensure knowing and intelligent waivers of the right to counsel, see Johnson v. Zerbst, 304 U.S. 458, 468, 58 S.Ct. 1019, 82 L.Ed. 1461 (1938) (holding that accused must “competently and intelligently” waive the right to counsel), we conclude that it is not clearly established federal law as determined by the Supreme Court, see 28 U.S.C. § 2254(d)(1), that such warnings are a constitutionally mandated prerequisite to every knowing and intelligent waiver of the right. Because Dallio does not assert that his waiver of counsel was not otherwise valid, nor would the record support such a conclusion, see infra at note 4, he fails to establish a right to habeas relief.
I. Background
A. Dallio Admits Murdering Loni Berglund
On January 10, 1986, in an apartment in Forest Hills, Queens, a young woman named Loni Berglund was killed by one gunshot wound to her chest and three to her head in the course of a robbery that netted its perpetrator fifty dollars. For more than five years, the crime went unsolved when, in May 1991, new computer technology matched fingerprints lifted from the murder scene to those of petitioner Thomas Dallio.
On October 15,1991, two New York City police detectives, Timothy Copeland and Raymond Pierce, interviewed Dallio, who was then incarcerated on a 1988 New York State robbery conviction. After waiving his Miranda rights, Dallio agreed to speak with the officers and, over the course of several hours, made a series of inculpatory audiotaped and videotaped statements. For example, in a 12:30 p.m. statement apparently addressed to Ms. Berglund’s mother, Dallio said:
I’m very sorry what happened to Loni. She was a beautiful person who reached out to me.... We were in the apartment _She said um it’s getting late. I thought about going back out there into the street with no money, no drugs, [556]*556no place to stay. So I pulled out the gun and I asked her to sit on the couch and I asked her where the money was. She couldn’t believe, she couldn’t believe that I was serious. She says is this for real ... she said she didn’t have any money. Then she got up like she was goin’ for the door. She was goin’ for the alarm and I fired first one time. She said something, she said okay, okay. I don’t know, I just fired again and again and again.... I know that I can’t bring her back. But I’m sorry an[d] I hope that you will forgive me, just like I ask God to forgive me.
Oct. 15,1991 Tape Trans, at 13-14.
Approximately six months later, on April 8, 1992, Dallio volunteered further inculpa-tory statements. While being transported from prison to a police station where he would formally be charged with Ms. Berg-lund’s murder, Dallio asked Detective Copeland about the likelihood of capital punishment in his case. When Copeland replied that petitioner could receive the death penalty, Dallio stated, “I killed her in a drug-crazed state. I didn’t mean to do it. I think I should get manslaughter not murder.” June 10, 1993 Hearing Trans, at 44. He further stated that his prior confession had been for the benefit of the victim’s mother, “nobody else,” and that but for his “confession and the prints,” the police would have no case against him. Id. at 45.
B. The Hearing to Suppress Dallio’s Inculpatory Statements
1. Representation by Defense Attorneys DiBlasi and O’Grady
After indictment, Dallio moved to suppress his admissions to the police as involuntary custodial statements made in violation of his right to counsel. A seven-day hearing was conducted over the course of almost two years. On the first four hearing days, June 9-10, 1993, and September 14 and 16, 1993, Detective Copeland testified and was extensively cross-examined by Dallio’s then-assigned counsel, Joseph V. DiBlasi. Dissatisfied with DiBlasi’s performance, Dallio filed a pro se formal motion in 1994 for new counsel, whereupon John J. O’Grady was assigned responsibility for the defense.
When the suppression hearing resumed on March 30, 1995, O’Grady cross-examined Detective Pierce. An issue then arose about Dallio’s desire to have Copeland recalled for further cross-examination. Addressing the court directly, Dallio cogently explained that he intended to testify at the hearing, that he understood that his credibility vis-a-vis the police officers would be critical to the court’s decision, and that, for this reason, he deemed it imperative that Copeland be impeached with various inconsistent prior statements. The court agreed to have Detective Copeland recalled.
2. Dallio Concludes the Hearing Pro Se
On April 19, 1995, before Copeland resumed the witness stand, O’Grady advised the court that Dallio had advised him, after an “in-depth conversation,” that he wished “to go pro se on this hearing.” Apr. 19, 1995 Hearing Trans, at 63. O’Grady explained that Dallio felt “very familiar with the manner in which to proceed on this hearing, and how he want[ed] to handle Detective Copeland.” Id. Acknowledging that Dallio might not have the competence of an attorney in conducting the hearing, counsel nevertheless voiced his opinion that Dallio was “competent to make [the] decision” to proceed pro se. Id. Dallio also addressed the court, reiterating his concern about the adequacy of prior counsel’s cross-examination of Copeland and questioning present counsel’s familiarity with certain materials and some of his strategic [557]*557decisions. Id. at 65-67. The prosecution accused Dallio of seeking to delay the case, whereupon the court inquired, “Are you ready to proceed now?” Id. at 68. When Dallio replied that he was, the court, without further discussion, permitted Dallio to proceed pro se with O’Grady serving as stand-by counsel.
Immediately, Dallio submitted a supplemental suppression motion to the court, explaining that he wished to ensure that “all grounds for suppression with particular specificity [were] raised and reserved on the record.” Id. at 68. O’Grady noted that Dallio was acting against his advice, which petitioner confirmed. Dallio then proceeded to cross-examine Copeland, consulting with O’Grady from time to time, but nevertheless drawing frequent objections for interspersing his questions about the witness’s prior statements with arguments about their inconsistency. Although the prosecution occasionally displayed exasperation, see id. at 76-77 (“Again, your Honor, this is not a proper line of questioning. The prior transcript is part of the record. And I think the questions that the defendant is asking illustrates his inability to go pro se in this matter.”), the court did not, patiently listening as Dallio explained his theory of cross-examination, and even telling him to “[t]ake your time,” id. at 88, until Dallio reported that he had no further questions for the witness.
Through O’Grady, Dallio requested and obtained court permission to take the stand and “testify in a narrative form,” id. at 92, to the circumstances under which he had made incriminating statements to police authorities, an account that covers fifty pages of transcript. At the conclusion of Dallio’s direct testimony, as well as at the conclusion of his cross-examination, the court asked O’Grady if he wished to pose any questions. Although counsel replied that he did not, O’Grady did ensure that Dallio had nothing more to say to the court before leaving the witness stand. Counsel also noted (and the trial court acknowledged) that “during the course of the proceeding that my client went pro se, I was available to him[. W]hen he questioned Detective Copeland I assisted and although he testified on direct in narrative form[,] I was here and available for consultation.” Id. at 176.
On the last hearing date, May 18, 1995, Dallio called two corrections employees, Donna Hunt and Scott Willis, to testify briefly to entries in prison records about petitioner’s movements on October 15, 1991, which evidence Dallio believed was at odds with the accounts of Copeland and Pierce about the time of their interview. When the prosecution attempted to rebut this evidence with the testimony of Edward Carroll, the corrections officer who had actually escorted Dallio to the challenged interview, Dallio conducted the witness’s cross-examination.
With the hearing thus concluded, Dallio addressed the court for over an hour in support of his suppression motion. Thereafter, the court inquired of O’Grady whether he wished to add anything. Counsel demurred, explaining, “I couldn’t say it better.” May 18, 1995 Hearing Trans, at 120. A few weeks later, on June 3, 1995, Dallio submitted a fifteen-page memorandum of law in support of his suppression motion, outlining six points with citations to legal authority.
On August 3, 1995, the trial court denied the suppression motion, ruling that Dallio’s inculpatory prison statements were knowingly and voluntarily made after waiver of the right to counsel and that his subsequent inculpatory statements were spontaneous and not the product of police interrogation. See People v. Dallio, No. 1368-92 (N.Y.Sup.Ct. Aug. 3, 1995).
[558]*558C. Dallio Obtains New Counsel and Pleads Guilty
On June 27, 1995, even before the trial court ruled on his suppression motion, Dal-lio filed a motion for appointment of new counsel, which was granted by the court.
On November 13, 1995, Dallio’s new counsel, Jonathan Latimer, advised the court that after extensive consultation, including discussions about the lost suppression motion and the admissibility of the inculpatory statements, Dallio wished to plead guilty. At no time during the allocution did counsel or Dallio (who addressed the court at length) challenge the suppression ruling or request a new hearing on the ground that Dallio had been permitted to proceed pro se without adequate warnings about the risks of self-representation. Neither was such a challenge raised at sentencing.1
D. Direct Appeal
On direct appeal to the Appellate Division, Second Department, Dallio raised, among other challenges, the claim that his Sixth Amendment right to counsel had been violated by inadequate warnings at the suppression hearing. Citing Faretta v. California, 422 U.S. at 806, 95 S.Ct. 2525, as well as a number of decisions by the New York Court of Appeals, Dallio’s new counsel, the Legal Aid Society, argued that no waiver of the right to counsel could be valid absent explicit warnings of the dangers and disadvantages of self-representation and that Dallio’s failure to receive such warnings required that his conviction be vacated.
In affirming Dallio’s conviction, the Second Department addressed petitioner’s suppression challenge to his inculpatory admissions but summarily rejected as “without merit” all other arguments, including the claim of inadequate warnings about the risks of self-representation. People v. Dallio, 256 A.D.2d 417, 418, 682 N.Y.S.2d 233, 234 (2d Dep’t 1998) (“The defendant’s remaining contentions are without merit.”). Counsel vigorously pursued the warnings point in a letter-memorandum seeking leave to appeal to the New York Court of Appeals. Leave was summarily denied on January 29, 1999, see People v. Dallio, 92 N.Y.2d 1048, 685 N.Y.S.2d 426, 708 N.E.2d 183 (1999), and, on March 19, 1999, the Court of Appeals denied Dallio’s pro se request for reconsideration, see People v. Dallio, 93 N.Y.2d 872, 689 N.Y.S.2d 434, 711 N.E.2d 648 (1999).
E.Federal Habeas Petition
On March 15, 2000, Dallio filed a timely federal petition for a writ of habeas corpus in the Eastern District of New York, challenging both the state court’s denial of his suppression motion and its decision to allow him to proceed pro se without explicit warnings about the risks of self-representation. In a thoughtful and detailed decision, the district court ruled that the first point was without merit. See Dallio v. Spitzer, 170 F.Supp.2d at 338-40. As to the second point, after carefully reviewing relevant Supreme Court and Circuit precedent, the district court ruled that “[a]l-though ... there is no rigid procedure for [559]*559advising a defendant about the ramifications of proceeding pro se, Faretta requires, at a minimum, that there must be an explanation of the attendant dangers and disadvantages.” Id. at 336. Because “[t]he trial court did not do this,” and because “[t]he record is devoid of any indication that Dallio understood the dangers and disadvantages of the choice he was making,” the district court concluded that the Appellate Division’s rejection of Dal-lio’s Sixth Amendment claim on its merits “amounted to an unreasonable application of clearly established Supreme Court law.” Id. at 336-37.
Nevertheless, because Dallio had not been “den[ied] ... the assistance of counsel altogether,” the district court concluded that the error was not “structural” and, therefore, not subject to per se reversal. Id. at 337 (citing Lainfiesta v. Artuz, 253 F.3d 151, 156-57 (2d Cir.2001) (“The Supreme Court has held that violations of the Sixth Amendment right to counsel are per se reversible only when they amount to an actual or constructive denial of the assistance of counsel altogether, or when counsel was prevented from assisting the accused during a critical stage of the proceeding.” (internal quotation marks and citations omitted)) and Coleman v. Alabama, 399 U.S. 1, 10-11, 90 S.Ct. 1999, 26 L.Ed.2d 387 (1970) (directing harmless error review of Sixth Amendment deprivation of counsel at a preliminary hearing)). Applying harmless error analysis, the district court noted the following facts: (1) the majority of the suppression hearing had taken place before Dallio elected to proceed pro se; (2) during the testimony of key witnesses Pierce and Copeland, “Dallio had already received the benefit of counsel’s skilled and thorough examinations;” (3) throughout the time Dallio proceeded pro se stand-by counsel was available to assist him; and (4) Dallio “ably represented himself’ in questioning witnesses. Id. at 338. From these facts, the district court concluded that the trial court’s failure “to warn Dallio of the dangers and disadvantages of proceeding pro se did not have a substantial and injurious effect on the outcome of the hearing” and that any Sixth Amendment violation was harmless error. Id.
Dallio moved this court for a certificate of appealability. On June 18, 2002, we granted the motion on the single issue whether Dallio’s “right to counsel was violated because the trial court failed to advise [him] of the dangers and disadvantages of self-representation.” Dallio v. Spitzer, No. 01-2718 (2d Cir. June 18, 2002).
II. Discussion
A. Standard of Review
Two standards are implicated in our review of habeas petitions filed pursuant to 28 U.S.C. § 2254. First, with respect to the district court’s decision denying Dallio’s § 2254 petition, our review is de novo. See Cook v. New York State Div. of Parole, 321 F.3d 274, 277 (2d Cir.2003). Second, with respect to state court rulings that underlie the habeas challenge, to the extent these rulings were made on the merits, our review is deferential as dictated by the Antiterrorism and Effective Death Penalty Act of 1996 (“AEDPA”), Pub.L. No. 104-132, 110 Stat. 1214 (1996). See Jenkins v. Artuz, 294 F.3d 284, 291 (2d Cir.2002) (and cases cited therein). The Act provides in pertinent part:
An application for a writ of habeas corpus on behalf of a person in custody pursuant to the judgment of a State court shall not be granted with respect to any claim that was adjudicated on the merits in State court proceedings unless the adjudication of the claim—
(1) resulted in a decision that was contrary to, or involved an unreasonable application of, clearly established Feder[560]*560al law, as determined by the Supreme Court of the United States; or
[2] resulted in a decision that was based on an unreasonable determination of the facts in light of the evidence presented in the State court proceeding.
28 U.S.C. § 2254(d).
Our precedents instruct that to qualify as an adjudication “on the merits,” a state court decision need not mention a particular argument or explain the reasons for rejecting it. See Brown v. Artuz, 283 F.3d 492, 498 (2d Cir.2002); Aparicio v. Artuz, 269 F.3d 78, 93-94 (2d Cir.2001); Sellan v. Kuhlman, 261 F.3d 303, 312 (2d Cir.2001). Where, as in this case, “there is no basis either in the history of the case or the opinion of the Appellate Division for believing” that the claim at issue “was denied on procedural or any other nonsub-stantive grounds,” a terse statement that “remaining contentions are without merit” suffices to trigger AEDPA’s heightened standard of review. Id.
Applying that standard to this case, we reject Dallio’s argument that the state court’s denial of his Sixth Amendment challenge to his pro se status at the suppression hearing “was contrary to, or involved an unreasonable application of, clearly established Federal law, as determined by the Supreme Court.” 28 U.S.C. § 2254(d).
B. Clearly Established Federal Law Does Not Mandate Explicit Warnings of the Dangers and Disadvantages of Self-Representation to Execute a Knowing and Intelligent Waiver of the Right to Counsel
Dallio’s habeas challenge to his pro se status for part of the suppression hearing implicates related Sixth Amendment rights: the right to counsel and the right to represent oneself. The right to counsel is explicitly safeguarded by the Sixth Amendment, which states that “[i]n all criminal prosecutions, the accused shall enjoy the right ... to have the Assistance of Counsel for his defence.” U.S. Const, amend. VI. It is clearly established federal law as determined by the Supreme Court that no defendant can be convicted and imprisoned unless he has been accorded the right to the assistance of counsel. See Powell v. Alabama, 287 U.S. 45, 53 S.Ct. 55, 77 L.Ed. 158 (1932); see also Johnson v. Zerbst, 304 U.S. at 467-68, 58 S.Ct. 1019, 82 L.Ed. 1461. Moreover, clearly established law applies this right to all “critical” stages of a criminal prosecution, including pre-trial hearings, Maine v. Moulton, 474 U.S. 159, 170, 106 S.Ct. 477, 88 L.Ed.2d 481 (1985) (and cases cited therein), without regard to whether the prosecution occurs in federal or state court, see Gideon v. Wainwright, 372 U.S. 335, 342-45, 83 S.Ct. 792, 9 L.Ed.2d 799 (1963).
Although not expressly stated in the Sixth Amendment, a clearly established corollary to the right to counsel is the “right to dispense with a lawyer’s help,” Adams v. United States ex rel. McCann, 317 U.S. 269, 279, 63 S.Ct. 236, 87 L.Ed. 268 (1942), and to represent oneself, McKaskle v. Wiggins, 465 U.S. 168, 174, 104 S.Ct. 944, 79 L.Ed.2d 122 (1984) (referring to “the long-standing recognition of a right of self-representation in federal and most state courts”). In the leading case on the right of self-representation, Faretta v. California, 422 U.S. 806, 95 S.Ct. 2525, 45 L.Ed.2d 562, the Supreme Court vacated a state court conviction precisely because a defendant’s request to proceed pro se was denied. The Court explained:
The Sixth Amendment does not provide merely that a defense shall be made for the accused; it grants to the accused personally the right to make his defense .... Although not stated in the Amendment in so many words, the right [561]*561to self-representation — to make one’s own defense personally — is thus necessarily implied by the structure of the Amendment.
Id. at 819, 95 S.Ct. 2525.
Although Dallio relies heavily on Faretta in support of his Sixth Amendment claim, his complaint is not that he was denied the right to self-representation. Rather, he asserts that his right to counsel was violated because the state court permitted him to proceed pro se at the suppression hearing without expressly warning him of the dangers and disadvantages of self-representation.2 Clearly established federal law requires that a defendant’s waiver of the right to counsel be knowing and intelligent. See Johnson v. Zerbst, 304 U.S. at 464-65, 58 S.Ct. 1019, 82 L.Ed. 1461. The issue on this appeal is whether clearly established federal law dictates as a minimum constitutional prerequisite to a knowing and intelligent waiver of counsel that a court explicitly warn a defendant of the dangers and disadvantages of proceeding pro se. We conclude that it does not.
The only Supreme Court support for this proposition is language in Faretta v. California that a defendant waiving his right to counsel “should be made aware of the dangers and disadvantages of self-representation.” 422 U.S. at 835, 95 S.Ct. 2525. Significantly, this quotation is not part of the holding in Faretta, but dictum in the case.3 The Sixth Amendment viola[562]*562tion specifically identified by the Supreme Court in Faretta derived from the state’s refusal to allow the defendant to waive his right to counsel, not from any defect in his particular waiver. While “general expressions” of law by the Supreme Court that go beyond the actual decision in the case may well merit respect, see Cohens v. Virginia, 19 U.S. (6 Wheat.) 264, 399-402, 5 L.Ed. 257 (1821) (rejecting arguments based on dicta in Marbury v. Madison), they do not constitute “clearly established law, as determined by the Supreme Court,” for purposes of § 2254(d) review. As the Court itself instructed in Williams v. Taylor, “clearly established Federal law, as determined by the Supreme Court ... refers to the holdings, as opposed to the dicta, of this Court’s decisions as of the time of the relevant state-court decision.” 529 U.S. 362, 412, 120 S.Ct. 1495, 146 L.Ed.2d 389 (2000) (internal quotation marks omitted); accord Morris v. Reynolds, 264 F.3d 38, 46 (2d Cir.2001).
In any event, we note that Faretta’s use of the word “should” in identifying warnings relevant to waivers of counsel itself cautions against interpreting the quoted language as clear establishment of a legal mandate. Although grammatically the word “should” is simply the past tense of “shall,” see Oxford American Dictionary and Language Guide, 931 (1999), in the legal context, the two words often convey quite different meanings. “Shall” is universally understood to indicate an imperative or mandate, see Black’s Law Dictionary, 1375 (6th ed.1990), whereas “should,” to the extent it implies any duty or obligation, generally references one originating in “propriety or expediency,” id. at 1379. Precisely because the word “should” is legally variable, compare United States v. Anderson, 798 F.2d 919, 924 (7th Cir.1986) (“[t]he common interpretation of the word ‘should’ is ‘shall’ and thus ... imposes a mandatory rule of conduct”) with Culbert v. Young, 834 F.2d 624, 628 (7th Cir.1987) (“[t]he word ‘should’ unlike the words ‘shall,’ ‘will,’ or ‘must,’ is permissive rather than mandatory”); and McDonnell Douglas Gorp. v. Islamic Republic of Iran, 758 F.2d 341, 347 (8th Cir.1985) (holding that “should” is a preferential rather than mandatory word and that contract provision stating that parties “should” settle disputes in a particular forum was not a mandatory selection clause), [563]*563we cannot infer from its use in Faretta the Supreme Court’s recognition of a clearly established prerequisite for a waiver of counsel.
This conclusion is reinforced by the context in which Faretta discusses what “should” be made known to a defendant waiving his right to counsel:
Although a defendant need not himself have the skill and experience of a lawyer in order competently and intelligently to choose self-representation, he should be made aware of the dangers and disadvantages of self-representation, so that the record will establish that “he knows what he is doing and his choice is made with eyes open.”
Faretta v. California, 422 U.S. at 835, 95 S.Ct. 2525 (quoting Adams v. United States ex rel. McCann, 317 U.S. at 279, 63 S.Ct. 236). The citation to Adams suggests that Faretta’s reference to what “should” be done in making a waiver record is more properly viewed as a strong admonition than as a legal mandate. This is because Adams expressly cautions against using rigid formulas to determine the validity of constitutional waivers: “The task of judging the competence of a particular accused cannot be escaped by announcing delusively simple rules of trial procedure which judges must mechanically follow. The question in each case is whether the accused was competent to exercise an intelligent, informed judgment ....” 317 U.S. at 277, 63 S.Ct. 236. Indeed, the Supreme Court has repeatedly emphasized that a knowing and intelligent waiver depends on the totality of “facts and circumstances” in a given case, Edwards v. Arizona, 451 U.S. 477, 482, 101 S.Ct. 1880, 68 L.Ed.2d 378 (1981) (quoting Johnson v. Zerbst, 304 U.S. at 464, 58 S.Ct. 1019), and it has generally rejected arguments urging adoption of per se waiver rules based on any single factor, see North Carolina v. Butler, 441 U.S. 369, 374-76, 99 S.Ct. 1755, 60 L.Ed.2d 286 (1979) (declining to replace totality of circumstances standard for assessing knowing and voluntary waiver of right to counsel with an “inflexible per se rule” requiring such waivers always to be explicit).
Thus, while our court has strongly endorsed Faretta warnings as a factor important to the knowing and intelligent waiver of counsel, see United States v. Fore, 169 F.3d 104, 108 (2d Cir.1999) (noting, in case involving waiver of counsel at trial, that court “should conduct a full and calm discussion with defendant during which he is made aware of the dangers and disadvantages of proceeding pro se ” (internal quotation marks omitted)), we have, at the same time, also rejected rigid waiver formulas or scripted procedures, id. at 107 (“district courts are not required to follow a formulaic dialogue with defendants wishing to waive their Sixth Amendment rights to counsel, and we decline to impose a rigid framework”), and emphasized that “knowing and intelligent” waivers depend on the totality of the circumstances, id. at 108 (because “ ‘knowing and intelligent’ waiver depends upon the particular facts and circumstances of the case and characteristics of the defendant himself,” a trial court should “carefully consider defendant’s education, family, employment history, general conduct, and any other relevant circumstances,” (internal quotation marks omitted)).4 To the extent this prec[564]*564edent appeared to send mixed signals, the able district judge concluded that Faretta warnings were a “minimum” requirement to ensuring a knowing and intelligent waiver of counsel. Dallio v. Spitzer, 170 F.Supp.2d at 336. Such a cautionary approach to counsel waivers would certainly be understandable, even laudable, were a district court itself addressing a criminal defendant intent on proceeding pro se. But in this case, our focus is only on whether a state court’s contrary ruling falls within the narrow scope of 28 U.S.C. § 2254(d).
Because neither Faretta’s holding nor its dictum clearly establishes that explicit warnings about the dangers and disadvantages of self-representation are a minimum constitutional prerequisite to every valid waiver of the right to counsel, and because there is no other challenge raised to Dallio’s knowing and intelligent waiver of this right,5 we conclude that the [565]*565state court’s rejection of Dallio’s waiver claim was neither contrary to nor an unreasonable application of clearly established federal law and therefore he is not entitled to habeas relief.
III. Conclusion
The judgment of the district court in favor of respondents is hereby AffiRmed.