The Pentagon late last week announced a successful intercept test of an element of the ballistic missile defense. The test, which took place off of Hawaii, is pictured above. The Defense Department’s Missile Defense Agency reports that it was the 26th successful “hit to kill” intercept for elements of the Ballistic Missile Defense System since 2001. Maybe such successes have become so common they no longer qualify as news for the other papers, though somehow we guess that if the test had failed, it would have made its way into The New York Times.

The missile defense program is an example of the inter-service cooperation that characterizes the modern military — the test involved soldiers of the Army ‘s Air Defense Artillery Brigade using a Navy Aegis sensor and the Air Force’s Space-Based Infrared Sensors system. It is a particularly vital effort at a time when Iran is testing missiles and advancing in its effort to build a nuclear bomb, and when there is a new effort at the State Department to delude Americans into thinking that North Korea is abandoning its nuclear program.

The test last week was of a Terminal High Altitude Area Defense, known as THAAD, which, as a Pentagon press release put it, “intercepts a ballistic missile target in the ‘terminal’ phase of flight — the final minute or so when the hostile missile falls toward the earth at the end of its flight.” That’s better than getting hit, but it isn’t as good as a boost-phase missile defense that would destroy the enemy missiles over enemy territory, rather than off the American coast.

It is a reminder of the wonders that American science and technology can achieve, and of the boldness and foresight of President Bush’s decision to pull America out of the Anti Ballistic Missile treaty, signed in 1972 with a power, the Soviet Union, that has since been vanquished. With a few notable exceptions, the Democratic position on missile defense has been one of steadfast opposition: one of the party’s presidential candidates and leaders on foreign policy matters, Senator Biden, actually took to the Senate floor in 1999 and doubted the ability of our defense establishment to make such a system work. “Ask yourselves whether missile defense will really make you safe,” he advised Americans. Senator Clinton, the Democratic front-runner, has criticized Mr. Bush for withdrawing from the ABM treaty, which severely restricted the development, testing, and deployment of missile defense systems.

Not even missile defense’s most ardent supporters claim that it alone will protect Americans, but it is a prudent part of a defense against the likes of Iran or North Korea or even an Al Qaeda operative who gets his hands on a missile or two. It could help defend embattled American allies such as Taiwan or Israel. As America embarks on a presidential campaign, it is a question for the candidates to be pressed on: whether they would support a system that hits to kill, or whether they would kill the system and leave Americans defenseless out of a misplaced loyalty to an outdated treaty struck with a defunct power.