Representatives Thomas Massie, a Kentucky Republican, and Ro Khanna, a California Democrat, introduced a bipartisan House resolution last week in a bid to curb President Donald Trump's ability to escalate tensions with Iran.After the U.S. military carried out strikes on three Iranian nuclear sites on Saturday, Massie told CNN that he believed the resolution would have enough co-sponsors to "be able to force a vote unless [House Speaker Mike] Johnson pulls some shenanigans."Why It MattersTrump on Saturday evening announced what he described as a "very successful attack" against three Iranian nuclear sites at Fordow, Natanz, and IsfahanThe president's decision came after Israel and Iran have exchanged consistent strikes since June 13. Israel had urged the U.S. to target Iran's nuclear facilities, saying that Tehran was moving close to creating a nuclear weapon. Iran maintains that its nuclear program is for civilian purposes—not for weapons.The strikes have sparked concerns from some Democrats and some Republicans about a wider war breaking out—with some lawmakers accusing the president of violating the U.S. Constitution with the strikes.What to KnowMassie and Khanna introduced their War Powers Resolution in an effort to prohibit U.S. military involvement in Iran last Tuesday, amid the backdrop of escalating tensions with Iran."The Constitution does not permit the executive branch to unilaterally commit an act of war against a sovereign nation that hasn't attacked the United States," Massie said in a press release announcing the resolution. "Congress has the sole power to declare war against Iran. The ongoing war between Israel and Iran is not our war. Even if it were, Congress must decide such matters according to our Constitution."Khanna shared similar concerns in a statement emailed to Newsweek on Sunday after the strikes on Iran moved forward."Stopping Iran from having a nuclear bomb is a top priority, but dragging the U.S. into another Middle East war is not the solution. Trump's strikes are unconstitutional and put Americans, especially our troops, at risk," the congressman said. "Congress needs to come back to DC immediately to vote on Rep. Thomas Massie and my bipartisan War Powers Resolution to ensure there is no further conflict and escalation."Senator Tim Kaine, a Virginia Democrat, introduced companion legislation to the House resolution the day before his House colleagues."It is not in our national security interest to get into a war with Iran unless that war is absolutely necessary to defend the United States. I am deeply concerned that the recent escalation of hostilities between Israel and Iran could quickly pull the United States into another endless conflict," the senator said in a press release.Full List of Members of Congress Backing the War Powers Resolution Representative Ro Khanna, a California Democrat Representative Thomas Massie, a Kentucky Republican Representative Alexandria Ocasio-Cortez, a New York Democrat Representative Val Hoyle, an Oregon Democrat Representative Rashida Tlaib, a Michigan Democrat Representative Pramila Jayapal, a Washington Democrat Representative Donald Beyer, a Virginia Democrat Representative Lloyd Doggett, a Texas Democrat Representative Greg Casar, a Texas Democrat Representative Ayanna Pressley, a Massachusetts Democrat Representative Delia Ramirez, an Illinois Democrat Representative Summer Lee, a Pennsylvania Democrat Representative Ilhan Omar, a Minnesota Democrat Representative Jesus "Chuy" Garcia, an Illinois Democrat Representative Nydia Velazquez, a New York Democrat Representative James McGovern, a Massachusetts Democrat Representative Chellie Pingree, a Maine Democrat Representative Mark Pocan, a Wisconsin Democrat Representative Veronica Escobar, a Texas Democrat Representative Paul Tonko, a New York Democrat Representative Becca Balint, a Vermont Democrat Representative Bonnie Watson Coleman, a New Jersey Democrat Representative Henry "Hank" Johnson, a Georgia Democrat Delegate Eleanor Holmes Norton, a Washington, D.C., Democrat Representative Sara Jacobs, a California Democrat Representative Janice Schakowsky, an Illinois Democrat Representative Lateefah Simon, a California Democrat Representative Christopher Deluzio, a Pennsylvania Democrat Representative Gwen Moore, a Wisconsin Democrat Representative Mike Thompson, a California Democrat Representative Yassamin Ansari, an Arizona Democrat Representative Bennie Thompson, a Mississippi Democrat Representative Luis Correa, a California Democrat Representative Betty McCollum, a Minnesota Democrat Representative Marcy Kaptur, an Ohio Democrat Representative Mark DeSaulnier, a California Democrat Representative Stephen Lynch, a Massachusetts Democrat Representative Andre Carson, an Indiana Democrat Representative Mary Gay Scanlon, a Pennsylvania Democrat Representative Joaquin Castro, a Texas Democrat Representative Maxwell Frost, a Florida Democrat Representative Al Green, a Texas Democrat Representative Debbie Dingell, a Michigan Democrat Representative Jamie Raskin, a Maryland Democrat Representative Melanie Stansbury, a New Mexico Democrat Representative Sylvia Garcia, a Texas Democrat Representative Teresa Leger Fernandez, a New Mexico Democrat Representative Diana DeGette, a Colorado Democrat Senator Tim Kaine, a Virginia Democrat What People Are SayingJennifer Kavanagh, senior fellow and director of military analysis at Defense Priorities told Newsweek: "Iran has several options when it comes to retaliation, but will need to weigh them carefully. A stronger response may be useful for signaling Tehran's continuing resolve to internal and external audiences but it could also bring further U.S. military action and deeper U.S. involvement. Iran could target U.S. military bases and personnel in the Middle East."President Donald Trump on Truth Social on Saturday evening: "ANY RETALIATION BY IRAN AGAINST THE UNITED STATES OF AMERICA WILL BE MET WITH FORCE FAR GREATER THAN WHAT WAS WITNESSED TONIGHT. THANK YOU!"Iranian Foreign Minister Seyed Abbas Araghchi wrote on X, formerly Twitter, on Sunday: "The United States, a permanent member of the United Nations Security Council, has committed a grave violation of the UN Charter, international law and the NPT by attacking Iran's peaceful nuclear installations. The events this morning are outrageous and will have everlasting consequences. Each and every member of the UN must be alarmed over this extremely dangerous, lawless and criminal behavior. In accordance with the UN Charter and its provisions allowing a legitimate response in self-defense, Iran reserves all options to defend its sovereignty, interest, and people."What Happens Next?Iran's foreign minister said after the attack that his country reserves "all options to defend its sovereignty." The U.S. military is preemptively preparing for any attack from Tehran in response.It's unclear whether the War Powers Resolution sponsored by Khanna and Massie, which aims to curb Trump's ability to take military action against Iran, will move forward in the House. However, with Republican control of both chambers of Congress, it is not widely expected to succeed.