As a U.S. campaign of military strikes against Houthi rebels in Yemen shows no signs of ending soon and questions mount about whether the United States is at war in the Middle East, some lawmakers are signaling they believe it's time for Congress to weigh in.
Four senators who have been leading voices on issues of war powers for years sent a letter to President Joe Biden on Tuesday questioning his legal authority and strategic reasoning behind the ongoing strikes.
"As tensions in the region rise, we believe that American participation in another war in the Middle East cannot happen in the absence of authorization by Congress, following an open debate during which the American public can be informed of the benefits, risks and consequences of such conflict," the senators wrote in the letter.
The letter was organized by Sen. Tim Kaine, D-Va., and co-signed by Sens. Todd Young, R-Ind.; Chris Murphy, D-Conn.; and Mike Lee, R-Utah.
The letter comes after the U.S. military has conducted at least nine strikes on the Iran-backed Houthis in Yemen in response to a Houthi campaign of targeting commercial ships in the Red Sea. The Houthis claim their attacks are in support of Hamas amid Israel's war against the militants in the Gaza Strip, but the Houthis have targeted merchant ships from around the world with no connection to Israel.
On Jan. 11, the U.S. and U.K. militaries bombarded more than 60 sites in Yemen that U.S. officials said were integral to Houthi radar, missile and drone capabilities. In the following days, American forces conducted several more strikes in Yemen that U.S. Central Command described as preemptive to destroy Houthi missiles before they could be launched, with the most recent preemptive strike coming Tuesday night.
On Monday, the U.S. and U.K. unleashed another large-scale strike on eight locations in Yemen, including what U.S. officials described as underground storage of advanced weapons.
After the first strike, Kaine released a statement that called the military action "understandable" given the Houthi threat to international trade and U.S. personnel in the Red Sea, but expressed concern about "a back and forth that could draw the U.S. closer to war."
Murphy similarly said in a written statement last week that, while he supported "limited action," the administration "is legally required to seek congressional authorization for sustained hostilities against Houthi forces under the War Powers Resolution."
On Tuesday, Kaine told reporters that the situation that has played out in the days after the first strike is exactly what he feared.
"There is no current congressional authorization of U.S. military action against the Houthis in the Red Sea or Yemen," Kaine said. "This has gone beyond just kind of a one-off self-defense. As soon as it's a prediction of, 'It's a back-and-forth and it's going to escalate more' -- this needs Congress now, I think."
Biden said last week that U.S. military strikes against the Houthis will continue even as he acknowledged they haven't deterred the Houthi attacks in the Red Sea.
The 1973 War Powers Resolution, passed in the wake of the Vietnam War to ensure Congress had a voice in future military conflicts, allows a president to introduce the armed forces into "hostilities" in certain situations without congressional authorization. But if Congress has not authorized the use of military force after 60 to 90 days, the president must withdraw U.S. forces. Congress can also, at any point, pass a resolution directing the president to remove American forces.
Congress last passed a war powers disapproval resolution in 2019 in an attempt to force then-President Donald Trump to end U.S. military support to Saudi Arabia in its fight against the Houthis. Trump vetoed the resolution, which in the Senate was sponsored by Murphy, Lee and Bernie Sanders, I-Vt. Meanwhile, Congress has not been able to muster enough support for any new war authorization bills since the 2002 Iraq War authorization.
In his War Powers Resolution-mandated notification to Congress about the Jan. 11 strike, Biden cited his constitutional authority as commander in chief to "protect United States citizens both at home and abroad and in furtherance of United States national security and foreign policy interests" as his legal justification. Biden has not sent formal notifications to Congress about any of the subsequent strikes explaining the legal authority.
The Pentagon has also been coy about how it is describing the situation unfolding in Yemen and the Red Sea. In a press briefing Tuesday, Pentagon spokesperson Maj. Gen. Patrick Ryder said he "wouldn't define it as a conflict" but rather "action that's being taken to disrupt and degrade Houthi capability to conduct attacks against the international community."
In their Tuesday letter to Biden, Kaine, Young, Murphy and Lee asked for an explanation in writing for the legal authority for all the strikes after the first one. They also pressed Biden on what his administration believes is "self-defense" if the strikes aren't deterring Houthi action, what the administration's legal rationale is for defending foreign ships, and what date the administration believes U.S. forces were "introduced into hostilities."
"The administration has stated that the strikes on Houthi targets to date have not and will not deter the Houthi attacks, suggesting that we are in the midst of an ongoing regional conflict that carries the risk of escalation," they wrote. "While the Houthis and their backers, namely Iran, bear the responsibility for escalation, unless there is a need to repel a sudden attack, the Constitution requires that the United States not engage in military action absent a favorable vote of Congress."
Related: Is the US Military at War with the Houthis and Iran-Backed Militias? The Answer Is Complicated.