The legislative agenda of the House Republicans for the next Congress has been unveiled this week. “Pledge to America” is a policy statement encompassing a wide range of issues from economy to health care to the plan to keep the nation secure at home and abroad. The pledge highlights the importance of a strong national defense and the need to fully fund a robust ballistic missile defense program to protect the U.S. homeland against strategic attack.

The document rightfully acknowledges that today’s world of existing and emerging new independent nuclear weapons states requires steps to protect the U.S. homeland. To fully fund missile defense is not just a political imperative but a constitutional duty. The policy statement notes that “while the threat from Iranian intercontinental ballistic missiles could materialize as early as 2015, the government’s missile defense policy is not projected to cover the U.S. homeland until 2020.” Thus, “critical” funding must be restored to protect the U.S. homeland and U.S. allies from emerging missile threats from Iran and North Korea, or a potential future coalition of aggressors.

Leaving the U.S. strategically vulnerable not only projects weakness but creates opportunities for rogues to blackmail America and threaten its allies. Despite this risk and being a nation at war, U.S. defense spending is near historical lows and is less than one-fifth of the federal budget. Moreover, defense spending and key defense priorities are being crowded out by growing domestic entitlements.

Worse still, and a little-known fact, ballistic missile defense spending is less than 2 percent of the defense budget. In its first year, the Obama Administration cut the Missile Defense Agency’s budget by over $1 billion. In addition, the Administration stopped the plan to expand the only boost-phase missile defense program left—the airborne laser, an aircraft capable of shooting down ballistic missiles with a high-energy laser. This platform is suitable for protection of the U.S. coastlines against ballistic missiles launched from ships or a “Scud in a bucket” scenario.

In addition, New START—a nuclear arms control agreement signed in April earlier this year between the Russian Federation and the U.S.—limits missile defense options for future U.S. Presidents. The limitations on U.S. ballistic missile defenses are clear from the Russian unilateral statement, the treaty’s preambular language linking strategic offensive arms with ballistic missile defenses, and Article V. Additional limitations on test-target missiles can be found in provisions of the treaty, protocol, and annexes.

New START represents an effective return for the U.S. to a Cold War policy based on nuclear retaliation and vulnerability that is completely unsuitable for the new strategic environment. In this new situation, prudence dictates that the U.S. move toward a policy that emphasizes defenses to protect its people, territory, infrastructure, institutions, and—to the best extent possible—its allies. The pledge represents a welcome return to the fundamental requirement that U.S. national security policy should be first and foremost about defending the American people. At the same time, it is forward-looking because it adapts U.S. national security policy to the threats that are arising.

Owen Graham and Michaela Bendikova from the Davis Institute at The Heritage Foundation contributed to this post.