Senate Democrats blocked the National Defense Authorization Act (NDAA) on Tuesday, preventing the annual $1.1 trillion defense policy bill from advancing to a floor vote amid partisan disagreements over U.S. military action and spending priorities.

The NDAA, a staple of bipartisan cooperation that authorizes defense budgets and policies, includes funding increases for military personnel, missile defense enhancements, and multiyear contracts aimed at stabilizing procurement for weapons manufacturers and military leadership. The bill also incorporates several Democratic priorities, such as expanded child care services for military families. It passed the Senate Armed Services Committee last month by an 18-9 vote, with ranking Democrat Jack Reed praising the measure for strengthening national defense and increasing accountability.

However, Senate Democrats opposed moving the bill forward in the full Senate, citing concerns related to the resumption of hostilities involving Iran. Senate Minority Leader Chuck Schumer pointed to recent White House notifications that American forces are engaged in strikes against Iranian targets and remain positioned for potential further conflict. Connecticut Senator Chris Murphy characterized the defense bill as effectively an authorization for war with Iran.

Democratic opposition is framed as a protest against escalating military actions and broader policy disagreements. Schumer argued that the NDAA is imbalanced and excludes adequate bipartisan input, while also criticizing the bill for insufficient domestic spending. He suggested his party would withhold support unless Republicans agreed to increase funding for domestic priorities.

Republican lawmakers countered that Democrats’ blockade undermines national security, especially given ongoing threats from Iran and other adversaries. Republicans noted that defense spending has grown substantially over recent years, with increases exceeding those in non-defense discretionary spending during the Biden administration. They accused Democrats of using national security legislation as leverage for unrelated political goals, warning that such tactics could embolden U.S. adversaries.

The standoff follows a pattern of similar conflicts in the Senate, including a prolonged impasse earlier this year that delayed the funding of the Department of Homeland Security. Democrats previously withheld a funding package pending concessions on immigration enforcement policies before allowing most DHS agencies to be funded, while Republicans subsequently employed budget reconciliation to secure funding for Immigration and Customs Enforcement and Customs and Border Protection.

Last month, Democrats also blocked the reauthorization of Section 702 of the Foreign Intelligence Surveillance Act, a critical tool used for foreign surveillance, citing opposition to a temporary appointment at the Office of the Director of National Intelligence. Critics argued that letting this authority lapse amid ongoing security concerns was unwise.

The deadlock over the NDAA comes as both parties prepare for the upcoming midterm elections, with polls suggesting potential Democratic gains. However, the ongoing disputes raise questions about the willingness of lawmakers to prioritize national security amid partisan conflicts.