The US is the only country with the GBU-57 Massive Ordnance Penetrator—a 30,000-pound bunker buster—and the B-2 Spirit stealth bomber capable of delivering it, making it uniquely able to target deeply buried sites like Iran’s Fordow nuclear facility. Israel lacks both the bomb and an aircraft to deploy it, prompting requests for US assistance. While the US did not join the conflict solely for this reason, its involvement is tied to strategic interests, alliance commitments, and its exclusive ability to neutralize Iran’s most fortified nuclear sites.