President Biden signed a nearly $770 billion defense bill on Monday, $24 billion more than he had requested, a setback for antiwar liberals whose efforts to expand social spending have been blocked by Democratic moderates in the name of fiscal responsibility.

Lawmakers increased spending in almost every part of the military, including new funding to counter China’s military expansion, initiatives to bolster the defense of Ukraine and billions in cash for the procurement of advanced aircraft, ships and high-tech hardware.

The bill, the National Defense Authorization Act, also contains a 2.7 percent pay increase for most service members, a broadly popular provision supported by even the dozens of progressives who opposed the legislation’s passage in the House.

The measure, which covers the fiscal year that started on Oct. 1, also changes the way the military handles many internal criminal investigations, particularly those involving sexual assault and sexual harassment.

Those provisions “are the most transformational thing that has been done by the House Armed Services Committee in my 25 years of service,” said Representative Adam Smith, Democrat of Washington and the chairman of the committee. “There’s a lot to be proud of in this bill.”

The measure passed the House and the Senate this month with wide bipartisan support, despite the liberal House members and the 11 senators who voted against it, citing its steep price tag and the stripping away of policy provisions that would have levied penalties against Russia and Saudi Arabia for human rights abuses, required women to register for the draft and cracked down on extremism within the uniformed services.

But Republicans did not get everything they wanted. Democrats blocked an effort by House conservatives that would have declared that Congress had “lost confidence” in Mr. Biden over his handling of the withdrawal from Afghanistan.

The bill overcame intense partisan and intraparty dysfunction that has plagued Congress this year: The Senate neither passed its own defense bill nor considered any amendments, denying lawmakers the chance to vote on several foreign policy issues.

Instead, top congressional officials huddled behind closed doors to cobble together a House bill that could quickly pass both chambers. Those involved in the effort expressed their relief on Monday.

Senator Jack Reed, Democrat of Rhode Island and the chairman of the Armed Services Committee, called the bill “a win.”

“It provides our forces with the resources and support they need to defend our nation,” he said in a statement.

Mr. Smith and others highlighted the criminal justice reforms as among the most significant in recent history, and predicted that they would do much to change an entrenched culture of cover-ups and favoritism in the military’s justice system.

The bill, for the first time, criminalizes sexual harassment in the military as an offense under the Uniform Code of Military Justice. The changes also mandate that a unit’s commander be removed from the decision-making process in a range of serious crimes besides sexual assault and harassment, and mandate independent investigations for murder, manslaughter and kidnapping, in an effort to ensure impartiality.

“These reforms, which are supported by longstanding advocates for survivors of the sexual assault crisis in the military, will take the prosecution of all sex crimes in the military away from the control of the military commander,” Mr. Smith said in a statement.

“Instead, qualified, independent, uniformed attorneys — ultimately overseen by the civilian service secretaries — will have the sole authority for charging decisions and the responsibility to prosecute those charges.”