It was more than a half-century ago that scientists working on the Manhattan Project detonated the world's first nuclear device.
The mushroom cloud that rose above the southern New Mexico desert on that fateful day, July 16, 1945, ushered in the atomic age.
Tuesday, Jan. 18, 2000, quite possibly, marked another milestone in the atomic age.
For on that day, the Pentagon undertook the most significant test so far of the National Missile Defense program.
It attempted to do what foes of missile defense have long insisted could not be done intercept a missile 100 miles above the Earth. It's a feat as improbable, the skeptics said, as intercepting a bullet with another bullet.
If this test over the western Pacific Ocean had been successful, it could have proven, over time, to be as significant as Trinity (the code name for the first atom bomb test).
Unfortunately, the test failed.
If it does someday succeed, missile defense could ultimately undo what Trinity begat 55 years ago the nuclear arms race. Indeed, if a foolproof, fail-safe system is developed (and deployed) that can intercept intercontinental ballistic missiles, then the threat of a hostile missile attack, a threat the American people have lived under since the dawn of the atomic age, is effectively eliminated.
As it is, U.S. officials warn that the United States could be the target of a missile attack from an unfriendly or unstable country in the very near future.
Just last month, in fact, Defense Secretary William Cohen gave a speech in Brussels to NATO defense leaders in which he explained why the United States is committed to missile defense.
He noted that North Korea and Iran will have the capacity to launch long-range missiles as soon as 2005. He also noted the recent, unsettling nuclear buildups by both India and Pakistan.
Meanwhile, National Security Adviser Sandy Berger candidly told a National Press Club audience last week that, while the United States is hopeful that "our former adversaries, China and Russia, will emerge as stable, prosperous partners," it is quite possible that either or both nations could emerge as military threats to this country.
That is why the Clinton administration has completely reversed its previous opposition to missile defense. It is essential, as Cohen said, "to both protect the United States from limited ballistic missile attack from a rogue nation and preserve the strategic balance between the United States and Russia."
Of course, there is still a ways to go before the United States actually deploys the foolproof, fail-safe missile defense system that would enable the American people to go to bed each night secure in the knowledge that they need not fear a missile attack from Tripoli, or Pyongyang or Baghdad.
But the Pentagon assures us that progress is being made. And they point to the successful missile intercept that they pulled off last October.
However, the skeptics note, the crucial targeting data was pre-programmed before the launch.
And when and if the day comes that Muammer Quddafi, or Kim Jong Il or Saddam Hussein sends a rogue missile hurtling toward Washington, or New York or San Francisco, the fate of those cities will depend on an interceptor using in-flight (rather than pre-programmed) targeting data from military satellites and radars to steer itself into the path of the incoming enemy missile.
That's why this test was so significant. It was as close to authentic as the Pentagon could make it. There was no pre-programming involved. The interceptor received targeting data from a new radar station on the Kwajalein Missile Range in the Marshall Islands shortly before it separated from its rocket booster, some 1,400 miles from its target in space.
Had this highly realistic test been successful, it would have proven that missile defense can and will work, just as Trinity proved that the atomic bomb could and would work.
What will make the test all the more important politically is that it is a major consideration in President Clinton's decision, expected by mid-year, as to whether or not to authorize deployment of the missile defense system.
If he does, the Pentagon will spend the next five years building a system of 100 interceptor missiles that can protect the United States from the limited ballistic missile attack to which Secretary Cohen referred.
And further down the road, the United States could very well deploy a national missile defense system that could repel a full-blown ballistic missile attack (rather than a few dozen or so missiles).
An obelisk marks the spot at the White Sands Missile Range in New Mexico where the first atomic bomb was exploded 55 years ago.
Maybe, years from now, an obelisk will stand at Kwajalein Missile Range in the Marshall Islands, marking the place where the first successful true-to-life missile defense test took place, commemorating the date when a world safe from nuclear missiles became a real possibility. (Copyright 2000 Newspaper Enterprise Assn. Joseph Perkins is a columnist for The San Diego Union-Tribune.)