Before we bogged down in Vietnam I got a letter from Wayne Morse, then a senator from Oregon, who said that hard as it was to believe, there might be several hundred Americans killed there. Even before the senator died, people stopped calling him nervous Nellie.

The average war is going to be "over by Christmas." The Civil War was supposed to be over in no time because (as everyone agreed) the Yankees couldn't fight, didn't know anything about horses and were not gentlemen.

World War I was supposed to be a jolly expedition, however brief (if you didn't enlist quick it would be over before you got there) to teach the kaiser a lesson. Korea was not even a war, just a police action, like Vietnam.

Excitement over the Persian Gulf is now everywhere, yet with little discussion on such basic questions as what a war might accomplish and what the various costs might be.

Instead there is daily speculation on what the president will or won't do, as if George Bush were the only relevant figure in the mathematics of war and peace. The American nation, you might gather from the press, should stand quietly in the dock until a wise president passes judgment.

As Henry Kissinger, a shrewd observer, pointed out some weeks ago, many questions will be raised as time passes and the euphoria of decisive action simmers down. Before war is decided on it would be well to consider some key points.

Would the removal of Saddam Hussein solve the oil supply problem? Would the expulsion of Iraq from Kuwait ensure steady future supplies?

How large an army is necessary to drive Iraq out? Will superior air power do the trick or will there, as usual, be a prolonged war on the ground?

How solid is citizen support -- as distinct from cries of go gettem, George. In Vietnam support was roughly total until all of a sudden the prevailing public view was to get out and never mind victory.

Does it make a difference what the casualty figures are? Would the nation readily accept 70,000 casualties? Any top limit?

What would be the role of nuclear bombs? They would not be used at first. But wars are full of surprises, as the Japanese discovered. Would the war go nuclear if it were necessary "to save American lives"? How many lives before the big weapons are called on?

Can we rely on the present alignment of allies? Are coalitions against us conceivable, depending on events we cannot now foresee?

Is terrorism within America a serious threat or a negligible risk? If biological weapons are used by enemy agents here, are we able to prevent the importation of germ warfare better than the importation of cocaine?

We know or believe Iraq has no nuclear power. Do we also know there is no way the Iraqis can acquire such weapons elsewhere?

If nuclear weapons are used, will that have any likely effects on our international relations after the war?

What, exactly, is the president's power as commander in chief? If great ventures go sour, what are the legal and practical limits of the chief's authority? Should the chief simply fade off like Lyndon Johnson, leaving his successor to muddle out, or are more troubling constitutional scenarios possible?

Assuming few Americans are killed and terrorist activity is minimal, does it make any great difference what the Arab casualties are?

What will be the role of Israel? Are we sure she will act as we wish?

Such questions are best explored by the nation -- presumably they have already occurred to the executive branch -- before sounding ultimate trumpets.

There are times a war is the only answer. Does anybody think negotiations could have swayed Germany from her course in the 1930s? The American nation as a whole supported that war to the end, even though the risk was substantial and the Allies might not have won.

By the grace of God and a bit of luck the war was won, but it would not have been won without the firmest and most intensely committed support of the American electorate.

Stupid little excursions into Grenada and Panama do not require any thought, and got none, but a war in the gulf is something else. Grenada did not have a million-man army, for one thing.

It is by no means clear to sane Americans that war is the only possible course if Saddam does not vacate Kuwait. As for high moral purposes, nobody would think twice about Kuwait or, for that matter, Saudi Arabia, except for oil. If we are to fight for oil then we should be certain that war would solve the oil problem.

In World War II we saw civilization going down the drain if we didn't fight. Do we have the same sense of commitment now?

President Bush has the dreadful and unaccustomed burden of thinking clearly, weighing risks accurately, judging the nation and the world realistically.

Of course, if there is war and all goes swimmingly there will be no problem at all as a practical matter. But people got tired of the light at the end of tunnel only recently. We had no business in Vietnam. Before fighting starts, maybe we should be agreed on why we are in the gulf and what precisely we expect to win.

As the nation ponders, the president will choose his photo ops carefully, and may well decide to stay out of speedboats and golf carts for a spell.