Customs officials seized 37 kilos of marijuana from Flores-Montano’s gas tank at the international border in southern California. The Ninth Circuit affirmed the grant of Flores-Montano’s suppression motion, holding that the Fourth Amendment forbids a fuel tank search absent reasonable suspicion. Here, the United States Supreme Court reversed, holding that the search did not require reasonable suspicion. The decision relied on by the Ninth Circuit employed a balancing test in regard to “routine” searches. Complex balancing tests to determine what is “routine” and what is “intrusive” have no place in border searches of vehicles. The Government’s interest in preventing the entry of unwanted persons and effects is at its zenith at the border. Therefore the Government’s paramount interest in protecting the border authorizes it to conduct suspicionless searches there. Flores-Montano’s privacy expectation is less at the border than in the interior, and the Government had the authority to remove, disassemble, and reassemble the vehicle’s fuel tank.