in the u.s., opponents of solitary confinement have argued (with varying success) that the practice violates prisoners’ constitutional rights. despite the long history of litigation over the practice, the supreme court has yet to definitively state whether or not solitary confinement is unconstitutional. the supreme court considered the constitutionality of long-term solitary confinement only once in the ‘‘wilkinson v. austin'’ case. in contrast to the supreme court's inaction, lower courts of the u.s. have imposed constitutional limitations on the use of solitary confinement. despite such limitations, the federal courts have refused to find that solitary confinement is per se unconstitutional. the u.s. has also effectively “insulated itself from any official sanction for international violations by not submitting to the jurisdiction” of committees that enforce the iccpr or cat.