On the morning of Feb. 28, Trump announced that the United States and Israel launched a joint attack on Iran, which killed Iranian Supreme Leader Ali Khamenei. Since then, Iran has launched attacks on civilian infrastructure and American bases in Arab states.

U.S. and Israeli airstrikes targeted government, missile infrastructure and military sites. According to CBS News, in his address to the public, U.S. President Donald Trump said that the goal of the attack was to eliminate Iran’s missile capabilities, navy, possibility of developing nuclear weapons and support of “terrorist armies” outside its borders.

According to CBS News, Trump said that the war will continue until his objectives are met, which he said expects to last four to five weeks. However, officials say that the operation may be completed sooner or later than the president anticipates.

In his address to the public, Trump encouraged Iranians to take over the government. As of March 4, Trump has released no plan for assisting a transfer of power following Khamenei’s death. According to the BBC, the death of the supreme leader, along with other high-ranked officials in the regime, will not automatically result in the end of the regime, so the future of Iran’s government is currently unknown.

Trump used his constitutional authority to engage in military action to carry out these attacks. However, Congress has not used its constitutional power to declare war. The legality of the war has been questioned; however, Secretary of State Mark Rubio said that eight members of Congress were notified in advance of the attacks, which follows the War Powers Act.

Still, some experts say that the president overreached his power. In a FactCheck.org article, Yale International Law Professor Oona Hathaway said that Trump can only use this power when the U.S. is being attacked.