If there is one question transfixing market watchers in America and in exchanges the world over it is this: what will become of American International Group?

The Treasury Department and Federal Reserve are wrestling with this multi-billion-dollar question. The answer will not only affect AIG, but probably the stock market, banks and a variety of businesses and governments holding AIG-backed insurance policies.

So, what do the presidential campaigns have to say about this test of leadership?

Next to nothing.

The only official comment from John McCain’s campaign is through spokesman Tucker Bounds, who says “no taxpayer dollars should be involved in a bailout of AIG.”

But a bailout is not on the table. So that doesn’t get matters very far.

But it’s more than Barack Obama’s campaign has to say, which is nothing.

On background, senior Obama economic advisers say any comment about AIG in the heat of this crisis would be “irresponsible.”

One adviser said: “None of us (in Obama’s inner circle) have access to AIG’s books. Therefore questions about what the government should do an unanswerable.”

A senior economic adviser to McCain’s campaign said there’s no way to evaluate the risk an AIG collapse would have on the markets, although he said many legitimately fear the effect could be “systemic.”

That means it could trigger other failures as capital markets tighten and short-sellers abandon once robust institutions that don’t have massive ready capital reserves.

What about a bridge loan, with repayment dates and interest charged? Does either campaign favor that remedy?

Not on the record. Not even on background.

A top Obama adviser said it’s simply too early to advise the Fed and Treasury whether it should use a loan to “backstop” AIG until it can find more capital and boost either its stock price or credit rating.

“At this late hour, there are no good options for the government or the private sector,” the Obama adviser said.

Certainly the Fed, Treasury and private firms evaluating AIG understand that. But they must wrestle with these issues in real time — possibly they have less than 24 hours to come up with a plan — while the presidential campaigns have the luxury of waiting to see what happens and offering pronouncements then.

A senior McCain adviser said the question about a bridge loan to AIG with repayment dates “was a good and hard one.” He then proceeded to paraphrase the late Massachusetts Sen. Paul Tsongas who would often say: “that’s a good, hard question, now let me see how I can avoid answering it.”

The truth is, neither presidential campaign wants to answer the AIG question. This is mostly because it can’t — campaigns can’t pry open AIG’s books like Treasury, the Fed and possible suitors can.

Campaigns can set broad principles or goals. But the truth of this fast-moving Wall Street crisis is this — forces are in motion that haven’t been seen before and government institutions are making moves never before contemplated (see Bear Stearns).

That’s why presidential campaigns enjoy politicking at times such as these. And why government institutions sweat bullets as they try to solve problems.