concurring.
The statute at issue expressly authorizes customs officials to “search any . . . envelope” at the border where there is “reasonable cause to suspect” the importation of contraband. 19 U. S. C. § 482. In view of the necessarily enhanced power of the Federal Government to enforce customs laws at the border, I have no doubt that this statute — requiring as a precondition to the opening of mail “reasonable cause to suspect” a violation of law — adequately protects both First and Fourth Amendment rights.*
I therefore join in the judgment of the Court. On the understanding that the precedential effect of today’s decision does not go beyond the validity of mail searches at the border pursuant to the statute, I also join the opinion of the Court.
As the Court notes, ante, at 623, postal regulations flatly prohibit the reading of “any correspondence contained in sealed letter mail of foreign origin unless a search warrant has been obtained . . . 19 CFR § 145.3 (1976).