Israel’s unprecedented attacks on Iran had at their core an elusive and high-risk goal: eradicating the country’s controversial nuclear program.

The Israeli air force struck storage and missile-launch infrastructure in western Iran on Sunday, Israel’s military said, as attacks in Iran entered a third day.

Israel unleashed airstrikes across Iran for a third day on Sunday and threatened even greater force as some Iranian missiles evaded Israeli air defenses to strike buildings in the heart of the countr...