With three U.S. troops killed and one missing in Jordan and Iraq over two days, the U.S. military death toll has risen to at least 17 since the Iran war began. On the 19th (local time), U.S. Central Command said that a U.S. base in Jordan was attacked on the 17th, leaving two U.S. troops dead and one missing. Central Command noted that the death toll could rise once identification is completed for remains found at the Jordan base attack site.
These U.S. military fatalities occurred as public opinion in the United States to "end the Iran war" has gained traction. In a Reuters/Ipsos poll earlier this month, 58% of Americans opposed airstrikes on Iran, while 37% supported them. A total of 51% of respondents said the United States is not worth paying the expense for this war. Expectations that U.S. involvement will drag on reached 79%, up 14 percentage points in four months from 65% at the end of March.
U.S. public opinion is particularly sensitive to U.S. military casualties. In a poll in early March, at the beginning of the war, 54% said they would be less likely to support military action if U.S. casualties occurred. At the end of March, opposition to deploying ground forces reached 76%.
Experts assessed that with casualties from the U.S. airstrikes on the 17th, U.S. troop deaths are shifting from a justification for retaliation to a political expense the Trump administration will face in the November midterms. In past major wars, the U.S. Congress either granted the president the authority to use force early on or formed an overwhelming single front backing the operation's objectives. Ahead of the Vietnam War, during the Gulf of Tonkin Resolution, the House voted 416-0 and the Senate 88-2 in bipartisan support. In the recent Afghanistan war, the authorization to use force won broad legitimacy with a 420-1 vote in the House and 98-0 in the Senate. The Iraq war also secured support exceeding 75% in both chambers.
For a war to gain justification, Congress must issue a war resolution with one voice. During the Gulf War, the U.S. military suffered 383 casualties. But after achieving a clear victory in a short period, President George H. W. Bush's approval rating rose to 89% after the war ended. By contrast, in Somalia in 1993, after 18 U.S. troops were killed in the Battle of Mogadishu in what was seen as unnecessary combat, the House voted 425-0 to pressure the Clinton administration to withdraw.
There are cases where U.S. military casualties directly translated into subsequent election results. At the start of the Iraq war in 2003, the George W. Bush administration's approval rating reached 72%. But as the prolonged conflict fueled the view that it was a mistaken war, approval for the Bush administration and the Republican Party to which Bush belonged plunged. The Democratic Party, by contrast, gained 30 House seats in the 2006 midterms, regaining the House majority for the first time in 12 years. Christian Grose, a political scientist at Vanderbilt University, said, "An analysis of vote-share changes by district between the 2004 presidential election and the 2006 House elections shows that the greater the number of U.S. military casualties in a district, the larger the drop in Republican votes."
In this Iran war, the U.S. Congress did not even grant the Trump administration separate authorization to use force. Instead, both the House and Senate passed resolutions calling for an end to the war, bolstering anti-war sentiment. On the 3rd of last month, the U.S. House passed the War Powers resolution urging President Trump to end hostile acts against Iran by a vote of 215-208. In that vote, four Republican lawmakers joined Democrats. The Senate then approved a resolution with the same intent on the 23rd of last month by a vote of 50-48. Reuters and others said, "If additional deaths occur, Republican defections could grow over the war budget and the deployment of ground troops."
The longer the Iran war drags on, not only U.S. military casualties but also economic opportunity expense such as inflation are likely to impose a significant burden on the Trump administration. A total of 60% of Americans expected gasoline prices to rise further due to the Iran war. George H. W. Bush, whose approval rating soared to 89% after the Gulf War victory, failed to win reelection the following year due to economic problems. Democratic strategist Mark Longabaugh told the political outlet The Hill, "Republicans have no message. All they are doing is defending a war that nobody wants and nobody supports," adding, "The war is consuming the Republican midterm strategy itself."