Is a state court objectively unreasonable, for purposes of 28 U.S.C. § 2254(d)(1), when it concludes that a capital defendant was not prejudiced by his counsel's failure to introduce evidence that a federal habeas court concludes is a "double-edged sword" that might "indicate future dangerousness" and which counsel may well choose not to introduce in any further proceedings.

Whether a state court is objectively unreasonable under 28 U.S.C. § 2254(d)(1) in concluding a capital defendant was not prejudiced by counsel's failure to introduce 'double-edged' evidence of fetal alcohol syndrome that may indicate future dangerousness