JERUSALEM — Iran fired a barrage of ballistic missiles at Israel on Tuesday evening in a major attack with little advance warning, sending Israelis scrambling for shelter as the security cabinet convened in a bunker and the United States readied forces to come to Israel’s defense.

The direct military strike on Tuesday came after senior military commanders of the Revolutionary Guards Corps convinced the country’s supreme leader, Ayatollah Ali Khamenei, that it was the only course of action if Iran wanted to appear strong, according to three Iranian officials.

The Israeli military said it intercepted most of the missiles, but a number of projectiles successfully penetrated the country’s aerial defenses.