If a vehicle that uses a patented invention is in the United States for the sole purpose of engaging in international commerce, then this vehicle qualifies as being “temporarily” in the United States, and 35 U.S.C. § 272 defines such use as noninfringing. Additionally, at the preliminary-injunction phase, once the accused infringer has posed a substantial question of invalidity, the patentee must demonstrate that the invalidity defense lacks substantial merit.