Almost everything President Bush said Thursday in his inaugural address is absolutely true in principle, just the way a speech wrapped in such pomp should be constructed.

“The great objective of ending tyranny is the concentrated work of generations” — that’s for sure — “The difficulty of the task is no excuse for avoiding it” — nobody will ever accuse Bush of being timid — “America’s influence is not unlimited” — you’re kidding! — “but fortunately for the oppressed, America’s influence is considerable, and we will use it confidently in freedom’s cause” — nobody really doubted this would be the case in Bush’s second term.

Practice, of course, is a lot different from principle, a fact that becomes soberingly obvious when examining the probable first test for this policy — Iran.

There are many scenarios for how the Iran situation could play out in the coming months, none of them desirable and precious few of them even tenable.

Most frightening is the prospect that Iran has nuclear weaponry or is close to developing it and that somebody with authority will use it. It’s not clear whether this prospect bears any resemblance to reality, but it cannot yet be discounted.

Vice President Dick Cheney said Thursday that an invasion of Iran by Israel is similarly undesirable. He’s probably right.

Prosecuting a war in Iran would be, in mild terms, a bad idea. Common sense suggests that U.S. armed forces stretched to the brink in Iraq would be (again, in mild terms) hard-pressed to take on a country with almost three times the population of Iraq and a military in proportion with that.

The unspoken hope of rationally thinking people is that diplomatic pressure from the United States, Europe, the United Nations and even the Iranian people will result in a reversal of Iran’s foreign policies and support for terrorism, perhaps through regime change. This is all the more likely to work if the United States takes diplomacy seriously — something for which Bush has, unfortunately, never shown an inclination.

So, we’re left with one scenario, which presumes that there is no nuclear proliferation in Iran. Here, Iran is left to its own devices and continues a tense but peaceful co-existence with its neighbors and the rest of the world.

But now that won’t work either. Bush pledged Thursday to “All who live in tyranny and hopelessness” that his country is going to rescue them and remove their oppressors. That perfectly describes Iran, a country that, for example, on Saturday persisted in its trampling of women’s rights by again keeping Iranian women from running in elections scheduled for June.

In short, there is no good way to proceed unless something changes. Given our options, it seems a change in the Bush administration’s stance on diplomacy — that is, a recognition that diplomacy exists — is the most logical and practical.