If President Bush knows what he's up to in the Persian Gulf, he's keeping it a Skull-and-Bones secret. He told congressional leaders this past week he's happy to give sanctions as much time as they need. War, he said, is the last thing on his mind.

So why double the force to a size we cannot supply, rotate and otherwise sustain for more than a few months? No one pretends the embargo will squeeze Saddam Hussein out in less than another year. Assembling an offensive tank armada makes sense only if we intend to issue an ultimatum, backed by invasion, before March.Bush says he needs the offensive threat to convince Saddam he means business. It's another way of saying, "Forget my lips, guys; sanctions won't hack it. I've got to scare him out."

He may be right but, unfortunately, a bluff won't do the job, either. Saddam's evil and ruthless but far from dumb. He reads us better than we read him. If we decide we're ready, he'll know it and make his choice. Bluffing merely encourages his belief that we lack stomach.

Meanwhile, the absurd prospect of a huge offensive army sitting idle for months while sanctions erode Iraq makes people wonder, "Hey, what's going on here? We don't need all this to defend Saudi Arabia."

The president's words offer few clues. Saddam has to go, he says, but he can't seem to make up his mind why. First, it was "great oil reserves" on which "our jobs, our way of life, our own freedom and the freedom of friendly countries" depend.

Then: "Some people never get the word. The fight isn't about oil; the fight is about naked aggression."

Next it was "Hitler revisited, a totalitarianism and brutality . . . embassies being starved, people being shot, women being raped."

And most recently: "To see that aggression is unrewarded" and restore "security and stability to the Persian Gulf."

All this contradictory incoherence frittered away what a month ago was a national consensus that our vital interest required securing the oil lifeline and discouraging further aggression.

Bush will have another chance to tell it like it is, simply and clearly, after his Thanksgiving trip. Pray he takes it, so an honest, no-tricks debate can begin. Unless the country believes in what we're trying to do in the Gulf, we may as well forget the whole thing.