The U.S. military has attacked major civilian infrastructure in Iran for the first time, following President Trump's threat to bomb the country "back to the stone ages". The attack on the B-1 bridge near Tehran signals a widening of the US military's targets and could be a first step towards attacks on energy, water, and transportation infrastructure. U.N. defense officials claim the attack was conducted for military purposes to prevent the Iranian armed forces from moving weapons across the bridge. The Iranian mission to the UN also criticizes the US and Israeli strikes against civilian targets in Iran.