As the US weighs joining Israel’s assault on Iran, questions are mounting over whether such an intervention could trigger regime change in Tehran – an outcome that risks splintering the country and sending shockwaves across the region.

An Iranian missile hit the main hospital in southern Israel early Thursday, wounding people and causing “extensive damage” but no serious injuries, the medical facility said. Israeli media aired footage of blown-out windows and heavy black smoke.

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.