Did you notice that Switzerland finally joined the United Nations? Its square flag is now flying alongside the symbols of 189 other nations.

I’m told that it took terrorism to dislodge the country of chocolate and watches from its Alps-encased commitment to neutrality. But when I got the news, forgive me, I had a single irreverent thought: Well, now that Switzerland’s joined the U.N., maybe we should, too.

Yes, I know. America was the virtual midwife of this body back in 1945. Our largest city is its capital city. Its ambassadors live close enough to have seen the dust rise from ground zero.

But on Thursday when President Bush switched from comforter in chief to commander in chief, challenging the United Nations to make Iraq obey U.N. resolutions, there were, surely, many among the colorful assembly with reason to doubt our allegiance to the international community.

When he said, “we want the U.N. to be effective and respected and successful,” did someone mutter that we still owe the U.N. dues? When he talked about the importance of enforcing international resolutions, did someone remember that the United States hasn’t yet ratified the children’s rights treaty or the women’s rights treaty?

Even when he announced that we are rejoining UNESCO, surely there were those who recall last spring when his administration nullified our country’s signature on the treaty establishing an International Criminal Court. And there are fresh memories from the U.N. summit in Johannesburg this month, when we looked like an environmental rogue state.

The subtext of the president’s speech to the U.N. was “act or we will have to.” Is it any wonder that many in the international community ask whether our country only wants nations united behind us? Not beside us.

After a hard year, our government has somehow segued from a war on terror to a war on Iraq. The evildoer named Osama has morphed into the evil threatener named Saddam. There’s been a sleight of policy hand and mind that many Americans have trouble following.

This change was dropped into the public air with a word here, a phrase there. The war-to-be talk was barely a mumble over the summer. As Andrew Card said in his unforgettable phrase, “From a marketing point of view you don’t introduce new products in August.”

But by Sept. 11, that mournful anniversary, the president’s marketing vocabulary had expanded subtly but completely. On Ellis Island, he didn’t just talk about terrorists but about “any terrorist or tyrant.” He didn’t say “al-Qaida” but talked about those who “threaten civilization with weapons of mass murder.”

At the U.N., Bush said “Saddam has made the case against himself.” But in marketing war to a very uneasy American public, the White House makes its unilateral case on two things that have changed most dramatically in 12 months: our imagination and our sense of vulnerability. The case rests on biological and chemical weapons but most of all, on nuclear fear.

“We don’t want the smoking gun to be a mushroom cloud,” Condoleezza Rice said. “The first time we may be completely certain he has nuclear weapons is when, God forbid, he uses one,” said her boss at the U.N.

These words bring an undeniable chill. There are nuclear weapons in Russia, China, France and Britain, and more in Israel, India and Pakistan. And North Korea yesterday’s worry may have access to material. Iran is surely interested.

But in our nuclear nightmare, do we remember that here, too, we’ve been in lone pursuit of a missile defense shield and new plans for mininukes? We’ve done far too little to secure the tons of material that could float onto an international “market.”

I’m very aware of what a dangerous, maybe even demented, man rules Iraq. There’s no doubt that Saddam wants nuclear weapons. But there is also little reason to believe he is any closer to a bomb than last year.

If I remain in a camp firmly labeled “The Unconvinced,” it’s not because I have too little imagination, but too much. I can imagine Pakistan toppled and replaced by a fundamentalist hand on the nuclear button. I can imagine Iraq as a lesson to other “tyrants” to get their weapons quickly.

And what I cannot imagine is an endless series of American-orchestrated “regime changes” as the solution to a world’s nuclear menace.

In 1945, when we were the only superpower, we deliberately created an international community. Now we are again the lone superpower. Only this time we are far too dismissive of “partners.” In a treacherous time, we face the same question: How far can we go when we go it alone?