"I don't agree with a missile defense system." Those words from Barack Obama in 2001 help explain his disturbing presidential decision to continue cutting our nation's missile defense funding.

Even as threats from North Korea, Iran and elsewhere escalate, Obama's budgets have shown he continues woefully to underestimate the value of a credible missile defense system.

Including his latest defense budget, the president has now proposed cutting nearly $6.5 billion from missile defense over his first five years in the White House.

The rogue missile threat to the United States and our allies is relentlessly expanding. North Korea is testing nuclear weapons and launching missiles over Japan.

Iran continues to pursue nuclear weapons, as well, while promising to destroy the United States and to wipe Israel off the map. The combination of missile technologies and weapons of mass destruction is a reality that threatens our country today.

The best way to negate these threats is a credible missile defense system that makes missiles and weapons of mass destruction less attractive to unpredictable bad actors like Iran and North Korea.

Regrettably, Obama is not only weakening our missile defenses today, he is gutting our future missile defenses. Missile technology will continue to evolve, and our nation must keep pace through investments in current and future technologies.

Instead, Obama has repeatedly cut missile defense development programs that could have helped the United States defend against future missile threats.

Frustratingly, Obama's lack of foresight means we both end up behind the technological curve, spending more money for the same technology down the road.

Earlier in his administration, Obama canceled the same missile interceptors that he is now adding, at an increased cost, to provide additional protection against North Korea. Unfortunately, that protection that could have been in place today will now be delayed till 2017.

Obama also canceled plans to provide additional missile defenses for the East Coast against the fast-moving Iranian threat. This approach is the antithesis of leadership.

Instead of weakening our missile defenses, we must continue investing in key capabilities and technologies.

First, Congress should support the full deployment of our ground-based interceptors, which Obama proposed. These missiles are a vital piece of the missile defenses of the continental United States.

Second, Obama and the Senate must stop delaying the development of an East Coast missile site that would strengthen our defense against Iran and shore up insufficient protection of the eastern United States.

Third, we should develop a space-based defense layer, as once envisioned by President Reagan, to destroy offensive ballistic missiles from space. Fourth, we should develop the capability to destroy missiles in the boost or launch phase when they are most vulnerable.

Lastly, we need to focus investments on developing technologies for the future of missile defense -- technologies like directed energy or rail guns, which can help us dramatically reduce the cost of defending against enemy missiles.

Those on the Left like Obama, who consider missile defense a bad thing, are deeply misguided. Missile defense does not start wars; it helps prevent wars.

During recent violence in Israel, the rocket defense system called Iron Dome limited the number of successful rocket attacks and helped keep the violence from escalating.

A good missile defense system reduces the chances of nuclear war and decreases the incentive for other bad actors to invest in or deploy missiles and weapons of mass destruction.

"Not agreeing" with missile defense is akin to not agreeing with locking one's doors or not agreeing with bulletproof vests. Unfortunately, we will always have rogue regimes -- like North Korea -- that will use weapons of mass destruction to threaten violence.

We need a robust missile defense system to keep America and her allies safe in this dangerous world. Anything less is a dereliction of duty and national security malpractice.

Congressmen Doug Lamborn, R-Colo., and Trent Franks, R-Ariz., are co-chairmen of the House Missile Defense Caucus.