Saturday’s U.S. strike on Iranian targets “was the easy part… once you’ve got a toe in the water, you’ve got a foot in the water and then you’re all the way in,” a foreign policy analyst told HuffPost.

The war moved into a potentially more volatile phase when the United States bombed three nuclear sites in Iran. On Sunday, Iran launched more missiles at Israel and vowed to defend itself.

Dmitry Medvedev, the deputy chairman of Russia's Security Council, said on Sunday that U.S. President Donald Trump had started a new war for the U.S. by attacking Iran.