Tim Tobin, a Minnetonka, MN attorney who specializes in insurance coverage, says a client has already asked him about the war exclusion issue. He declined to identify or describe the client.

The issue is what constitutes "war" under the terms of the insurance policies, Tobin says.

On the one hand, the scale of the attack and the huge loss of life and mass destruction in the attacks has led some, including President George W. Bush, to declare it an "act of war."

But war is "open armed conflict between countries or between factions within the same country," says Webster's New World Dictionary. Tuesday's attack would appear not to fit this definition unless it can be shown that another country was behind it or that the attackers are a faction of U.S. citizens.

Tobin predicts the war exclusion issue will ultimately have to be sorted out by courts. Some insurance and reinsurance companies may be pushed into insolvency by their exposure to the incident, and will feel obligated to push their claim. Other insurers have already said they would "owe it" to their shareholders to pursue this argument, especially if some of their peers do so.

But Thomas disagrees. He anticipates the issue will be raised privately by insurers and may lead to some compromise, but he doubts it will ever to trial. After all, the public would poorly receive such a move by insurers.

"There may be litigation," Thomas says. "But if I had to pick, I would rather be arguing for the insured than the insurer."