Can anyone come up with a more chilling oxymoron than the one the Bush White House has made a centerpiece of national security in the new millennium — tactical nuclear weapons?

What are they thinking? Oh right, the initiative — nukes you can use, limited Armageddon — will “help lay the foundation for transforming the nation’s Cold War-era stockpile into a modern deterrent suited for the 21st century.”

That’s reassuring. As we march into the new century waging our endless war on terror, I guess we’ll be needing 5-kiloton battlefield missiles and Robust Nuclear Earth Penetrators, aka bunker busters, because, as Defense Secretary Donald Rumsfeld explained to Sen. Carl Levin earlier this year: “The world is experiencing an enormous amount of underground tunneling and activities.”

And we can’t let that happen. Apparently our enemies are developing and hoarding the wherewithal to kill us, or secreting their demonic leaders, in a furtive, shell-hardened underworld, but if we do enough research and spend enough money, we can smoke them out — with a tactical weapon that has the potential to kill and irradiate no more people than Little Boy, the bomb we dropped on Hiroshima. This is what nuclear visionaries call a clean bomb.

While what’s clean and what’s dirty is, perhaps, debatable, what’s truly troubling, as far as I’m concerned, is that the question Rumsfeld answered is not the one Levin had asked. The occasion was a Senate Armed Services Committee hearing last February on the defense budget and the newly released Nuclear Posture Review, which put seven countries into our nuclear crosshairs.

Levin said, “If the United States sends signals that we’re considering new uses for nuclear weapons, isn’t it more likely that other nations will also want to explore greater use or new uses for nuclear weapons, and that the other nations won’t listen to our pleas to stay non-nuclear or to stay in the nonproliferation treaty, but rather would say, ‘Well, you’re … looking at new ways to use nuclear weapons. Why shouldn’t we?”‘

Rumsfeld’s unwillingness or inability to answer this question directly — the simple answer to which would be yes — lays bare the heart of the great nondebate of our age: Does safety lie in overwhelming, godlike power over others, and the ability to thwart and obliterate their every nefarious countermove, or does it lie in basic human psychology, i.e., employing the Golden Rule and, at the very least, sensible panic management?

In game theory, the way that Rumsfeld and the militarists have defined the war on terror would be called a zero-sum game. There’s one winner, one loser, and every incremental gain comes only with a corresponding loss to the other side. Thus, if the opponent is going underground, we’ve got to nuke him out. Removing his incentive to do so in the first place doesn’t even enter into the thinking.

And Rumsfeld and Levin were two ships passing the night.

Those of us who oppose (understatement of the millennium) the Bush administration and its simplistic, zero-sum worldview depend, desperately, on our elected reps to articulate and press home the need for complex, trust-based security planning.

The ghastly fact of the matter is that the most important debate of our time — what, exactly, constitutes “a modern deterrent suited for the 21st century”? — is taking place covertly, out of earshot and interest.

And so, on Sept. 16, Senate Republicans, with the help of a few Democrats, pushed through funding for part of the Bush nuclear agenda (including bunker buster weaponry), over objections such as those raised by Sen. Dianne Feinstein, who said: “This is the beginning. This money will go to field a new generation of nuclear weapons. We should not do this.”

Ho hum. It’s only research. And these are small nukes.

Robert Koehler is an editor at Tribune Media Services. His e-mail address is bkoehler@tribune.com.