In late May, the Missile Defense Agency shot down a mock intercontinental ballistic missile with another missile. It was the equivalent of hitting a bullet with a bullet – in space.

The successful test confirmed that our country is making good progress in developing an effective missile defense system. And effective missile defense is needed now more than ever.

The Obama administration allowed the U.S. ballistic missile defense enterprise – in reality, several systems tied together – to pretty much lie fallow for years. At the same time, both North Korea and Iran continued to advance their ballistic missile technology and their nuclear programs.

To keep ahead of these existential threats, Congress and the Trump administration must fully fund critical missile defense projects, particularly the Redesigned Kill Vehicle – the good guys' bullet for the intercontinental ballistic missile.

Naysayers have lambasted the missile defense program since Ronald Reagan first endorsed the concept in his "High Frontiers" speech. They've complained that it's technically impossible – despite the ever-increasing number of successful tests.

And they've carped that some elements of the planned system have been deployed even though the technology was immature.

That latter point is technically correct but also irrelevant. America cannot risk the luxury of keeping missile defense in the lab until it is perfect. Given existing threats, it was simply prudent to deploy the defenses available – imperfect though they are – to give the American people as much protection as possible. Very real threats existed then, and even greater threats exist today.

Missile defense opponents also say that deploying these defenses is "provocative," that it makes the Russians and Chinese "uneasy." To be blunt, who cares?

The Russians have been briefed repeatedly and in great detail. They know the system is no threat to counter their nuclear capabilities. The Putin regime makes an issue of it purely for domestic political purposes.

China likewise knows the present level of missile defense isn't capable of stopping their missiles. The bottom line is that America's leaders have a responsibility to protect American lives, not placate other nations or stroke egos.

These same critics, mainly hardcore arms-control adherents, say that mutually assured destruction is actually a better deterrent, so why add ballistic missile defense to the mix?

Deterrence is still there, as far as Russia and China are concerned. But it's much less than a sure thing when applied to Iran and North Korea. The ideologies prevalent in these two rogue states provide no assurance that their leaders will be restrained from launching nuclear weapons by the prospect of their own nations' destruction.

It's telling that the arguments raised against today's ballistic missile defense program are the same as those raised more than 30 years ago. Even though the technology has made tremendous strides – and the risk of missile attacks have increased – opponents remain stuck in a 1980s mindset.

So how should we look at ballistic missile defense today? Here's an apt analogy. When ground soldiers move out on a mission, they put on their helmets and body armor.

This equipment provides a huge amount of protection, but not complete protection. The defense they afford is "immature" and "imperfect." If the enemy fires fast and often enough, he may still hurt those soldiers. But no one says we should ditch the body armor.

Ballistic missile defense, and particularly the ground missile-defense system, is America's body armor.

It is only prudent to use what we have, while continuing to seek improvements and lessons learned from testing. Wringing our hands over hostile governments' opinion of our efforts to protect American lives is ludicrous, especially when those governments are actively pursuing ballistic missile offensive capabilities of their own.

No one wants war with Iran or North Korea. But policymakers must reject the time worn, out-of-touch arguments of the naysayers. They should fully fund missile defense programs that can maximize our protection today and keep building on the latest successful test to usher in even more effective missile defense in the future.