Trump orders strikes on Iran; experts say he can bypass Congress (for now)

Trump characterized the joint operation with Israel to take out Iranian leaders and eliminate Iran's weapons supply as an act of "war," bringing into focus the 1973 War Powers Resolution and the 2001 Authorization for Use of Military Force (AUMF). Experts say those laws and court precedent have given Trump the authority to sidestep the legislative branch and attack Iran, for now.

"That was certainly the case with the attacks in Bosnia and Libya under Democratic presidents."

"Congress can seek to bar or limit operations in the coming days," Turley wrote. "Given the fluid events, many members are likely to wait to watch the initial results and, frankly, the polling on the attacks. … The longer the operation continues, the calls for congressional action will likely increase."

Noronha said that, unlike other iterations of the AUMF, the 2001 version of the law was never repealed and "expressly authorizes force against any nation, organization, or person that planned the 9/11 attacks 'or harbored such organizations or persons.'"

"Congress has had 25 years to limit the scope of the 2001 AUMF," Noronha wrote. "Instead, it has consciously decided to preserve the President's rights under the law to pursue international terrorists to the end of the earth."

Trump said in a statement early Saturday morning that Operation Epic Fury was a "noble mission" and that service members could be killed, explicitly using the term "war."

"The lives of courageous American heroes may be lost, and we may have casualties. That often happens in war," Trump said.

Some have suggested that, in planning the operation, Israel and the United States deliberately delegated responsibilities to avoid legal landmines.

A U.S. official told Fox News the Israeli military is targeting Iranian leadership, while the United States is targeting missile sites that pose an "imminent threat" rather than Iran's leadership. 

Amos Yadlin, a retired Israeli Air Force general, also told Fox News that Israel carried out a strike on Iran's leadership because of decades-old U.S. laws restricting the targeting of heads of state.

The White House, meanwhile, has made clear that it factored Congress into the planning. 

"The Trump administration must explain itself to the American people and Congress immediately, provide an ironclad justification for this act of war, clearly define the national security objective and articulate a plan to avoid another costly, prolonged military quagmire in the Middle East," Jeffries said.

Sen. John Thune, R-S.D., commended the president, citing Iran's "relentless nuclear ambitions" and refusal to engage in diplomacy.

Paul quoted President James Madison: "The Executive Branch is the branch most prone to war, therefore, the Constitution, with studied care, delegated the war power to the legislature."

A bipartisan group of lawmakers, including Jeffries, Senate Minority Leader Chuck Schumer, D-N.Y., and Rep. Thomas Massie, R-Ky., said they are planning a forthcoming vote on a war powers resolution that would block U.S. action in Iran without congressional approval. 

Previous attempts to pass the same bill failed this Congress after Trump launched targeted strikes on Iran's nuclear sites and captured Venezuelan leader Nicolás Maduro.

Fox News' Jen Griffin and Efrat Lachter contributed to this report.