The news that America is activating its missile defense shield in response to North Korea’s threat to test a long-range missile is a reminder not only of the stakes in the face-off with Korea; who, after all, is prepared to warrant that the missile is not going to be toting a payload to Seattle? It’s also a reminder of the way in which sometimes abstract political debates over arms control really do matter when it comes down to the basic safety of Americans. For if it were up to the Democrats, if it hadn’t been for the visionary leadership of President Reagan and his ideological heirs, there wouldn’t be a missile defense shield to deploy.

Consider the record of the two stalwart senators from New York, Charles Schumer and Hillary Clinton. They style themselves, and with a certain amount of accuracy, as the centrist, national security hawks among the Democrats. After the attacks on New York on September 11, 2001, both Mr. Schumer and Mrs. Clinton voted to authorize the Iraq war and the funds to fight it. But on missile defense, there’s not much difference between the senators from New York and the Howard Dean-Russell Feingold wing of the Democratic Party.

Back when President Clinton was in office, Mr. Schumer was using his Senate seat to join hard-left senators like Mr. Feingold and Senator Boxer in a letter asking Mr. Clinton to delay deployment of missile defense. Quailed the July 26, 2000, letter from Mr. Schumer to Mr. Clinton, “We fear that a decision to deploy would imperil, not improve, our national security. Both Russia and China have said they will respond with a new buildup of their own nuclear forces. Furthermore, our allies have expressed grave concern about the impact deployment would have on international strategic stability.”

Mr. Schumer’s letter concluded, “Mr. President, the most effective way to reduce the threat of nuclear weapons is by continuing our arms reduction agreements and by working aggressively to stop the spread of nuclear weapons and missile technology. We hope you will continue your efforts to preserve the ABM treaty and resist pressure to deploy a national missile defense system at this time.”

Even after September 11 demonstrated the threat to America, Mr. Schumer kept voting against missile defense. On June 17, 2004, he joined Mr. Feingold in voting for an amendment offered by Ms. Boxer that would have delayed the deployment of a missile defense until there was “operationally realistic testing”- a demand that was just a guise for delay. On June 22, 2004, Mr. Schumer again joined Senators Boxer and Feingold in trying to strip $515.5 million in funding from missile defense. On June 23, 2004, Mr. Schumer again tried to delay spending on missile defense, this time joining Mr. Feingold and Ms. Boxer in trying to hold back $550.5 million in missile defense spending under the guise of yet another “testing” requirement.

Then there’s Mrs. Clinton. In a 2004 speech to the Brookings Institution on “Addressing the National Security Challenges of Our Time,” the junior senator from New York criticized the Bush administration from withdrawing from the Antiballistic Missile Treaty, which was signed in 1972 by Richard Nixon and Leonid Brezhnev and was interpreted as banning America from deploying a missile defense.

Mrs. Clinton has tried on missile defense, as on so many issues, to straddle both sides, a fact New Yorkers are starting to recognize and that is no doubt responsible for her plummeting approval ratings among New Yorkers. On June 17, she sided with Republicans and the few genuinely centrist hawkish Democrats – Zell Miller, Joseph Lieberman – in a pro-missile defense vote. But on the June 23 and 22 votes, she turned around and joined Messrs. Schumer and Feingold and Ms. Boxer on the anti-missile-defense side.

Maybe Senators Clinton and Schumer were reading the New York Times, which in December 2002 pronounced that “rushing” to construct a missile defense was “premature.” Advised the Times editorial, “It would have made more sense to wait.” For what could the editors of the Gray Lady be waiting – for Kim Jong Il to strip down to his underwear and fetch up as the Naked Cowboy, strumming a guitar and yodeling Joan Baez songs in Times Square? The serious answer is that we are watching an extraordinary moment in the showdown unfolding as America, for the first time, switches on its anti-missile defenses. It is one of those moments when the country will begin to understand the depth of President Reagan’s understanding of the dynamics of the nuclear age.