However, the crown jewel of the Islamic Republic’s nuclear programme, a sprawling uranium enrichment facility built deep under a mountain in Fordow remains out of reach of Israel’s conventional weapons. It can only be destroyed with American “bunker-buster” bombs carried by B-2 Stealth fighters.

Ayatollah Ali Khamenei rejected President Trump's demand for unconditional surrender, as Iranians jammed the highways out of Tehran.

“If the Middle East is unstable, the world will not be at peace,” Chinese President Xi Jinping said Thursday. “If the conflict escalates further, not only will the conflicting parties suffer greater losses, but regional countries will also suffer greatly.”

For years, Israel contained its conflicts with Tehran, Hamas and Hezbollah. The broad assault on Iran highlights a shift in strategy.

As the attacks by Iran and Israel continue into their sixth day, here's a look at what we know about the conflict, and if the US will deploy troops.