The United States has thousands of troops deployed on bases across the Middle East, a region in which Washington's forces have carried out repeated military operations in recent decades. Israel launched an unprecedented air campaign against Iran last week, and US President Donald Trump has said he is weighing whether to join Israel in the fight. US involvement in the conflict would likely result in attacks by Tehran on American troops in the region, who have already been targeted by Iran-aligned forces in the course of the Israel-Hamas war.