As appropriations bills move through Congress, protecting important programs and eliminating wasteful spending is on everyone’s mind. When it comes to smart budget cuts, look no further than nuclear weapons programs.

The B61 nuclear bombs deployed in Europe are a particularly glaring example of a program that drains billions of dollars from the defense budget but does nothing to advance our security.

Nuclear weapons in Europe are an oddity, a footprint of the Cold War. But from a national security perspective, their usefulness disappeared with the Berlin Wall. We can’t afford to spend billions of defense dollars on programs that don’t defend us against today’s threats. Instead of supporting Cold War relics, we should be investing in tools to address 21st-century security challenges.

These challenges are very real and very different from those we faced 20 years ago. Today, we think less about the risk of major nuclear conflict between the United States and Russia. But we think more about the risk of nuclear terrorism. We don’t talk about communist spies infiltrating Congress. But we do talk about climate change, cyberattacks and other unconventional challenges to our security. We don’t do “duck and cover” any more. So why are we investing billions of dollars to keep nuclear bombs in Europe?

Cold War thinking and budget inertia have combined for the worst possible scenario: As the broad defense budget declines, the nuclear budget is about to explode. The United States is on track to spend more than half a trillion dollars on nuclear weapons and related programs over the next 10 years.

Expensive, unnecessary nuclear programs such as the B61 are threatening to squeeze critical defense programs out of the budget. We’re planning to spend more than $10 billion dollars on the B61, while underinvesting in important programs such as nuclear terrorism prevention and next-generation biofuels to reduce our dependence on oil.

Eliminating the B61 and other nuclear programs that don’t advance U.S. security interests will free up funding for other defense priorities. Cutting the B61 for tools our troops can actually use — that’s a tradeoff any smart military strategist would make.

In fact, military leaders have been at the forefront of a growing consensus for updating our nuclear strategy for the 21st century. Retired Gen. James E. Cartwright, former vice chairman of the Joint Chiefs of Staff, recently commented, “The world has changed, but the current arsenal carries the baggage of the cold war.”

Lt. Gen. Dirk Jameson, former commander of U.S. Strategic command, also highlighted the mismatch between nuclear capabilities and current security requirements. “Having more weapons doesn’t mean we are ‘winning’ — or will even succeed in deterring others from pursuing nuclear weapons. It merely reflects that our nuclear strategy is ill-suited to our times,” he recently wrote.

Military leaders have raised the call for a new nuclear strategy. Now it’s time for Congress to do their part. The Senate is on the right track with an appropriations bill that cuts $168 million from the request and requires an assessment of alternatives to the B61. Sens. Dianne Feinstein and Lamar Alexander, chair and ranking member of the Appropriations subcommittee that oversees nuclear weapons activities, should be proud of this step towards fiscal responsibility.

If their colleagues in Congress have the same interest in protecting taxpayer dollars, they will look carefully at the nuclear weapons budget and cut wasteful programs such as the B61.

Terri Lodge is the director for nuclear security at the American Security Project, a nonpartisan think tank focusing on national security issues, and a former State Department official.