The Senate vote on the Comprehensive Test Ban Treaty (CTBT) was more than just the defeat of a flawed agreement, it signaled the coming of age of a majority of Americans on the futility of trying to defend the country through arms control.

The Senate has traveled a long and tortuous road from its ratification of the Anti-Ballistic Missile (ABM) treaty in 1972 by a vote of 88-2 to its defeat of President Clinton's CTBT in 1999 by a near party-line vote of 51-48. This is not just a Senate transition. The vote reflects the concerns of many Americans who have had enough of the arms control nostrums favored by the liberal elite of the Democratic Party.

The ABM treaty has taught us the folly of promising to ban forever certain weapons or defenses and limit the use of new technologies. The arms control lawyers who carefully crafted that treaty nearly three decades ago committed future presidents never to defend the country against ballistic missiles. Then they added details banning forever sea-based, air-based, space-based, and mobile ground-based defenses, and said if new technologies like lasers were perfected we would have to negotiate with the Soviets before deploying them.

Did they have a crystal ball that told them we never would have to worry about some madman in Iran, Iraq, Libya, North Korea or China? Did they think missile technology would never spread? The ABM treaty was signed with the Soviet Union alone. Did they think the Soviet Union would last 1,000 years? Today the Soviet Union is no more, but the ABM treaty lives on, still blocking effective missile defenses for this country. The drafters of the ABM treaty said not to worry, we always could withdraw from it by giving Moscow six months notice. That proved easier said than done.

The treaty took on a life of its own. Now it is a symbol of strategic stability for Mr. Clinton and his new strategic partners in Moscow and Beijing. Despite numerous intelligence warnings that the Soviets were violating the ABM treaty, the evidence always was too ambiguous. No one was willing to abandon a treaty when cheating could not be proved beyond a doubt. But eventually there was proof: Moscow deliberately violated the treaty by building an enormous battle management radar at Krasnoyarsk.

The CTBT would have been even more difficult to verify. Low-yield nuclear tests can be conducted in underground caverns in ways that make detection almost impossible. …