Given the recent obsession with the 9-11 commission testimony, you’d think someone might ask why there has not been another attack since that day in the United States.

Perhaps the lack of any public discussion about that issue is due to an understandable desire not to jinx ourselves.

Or maybe it stems from the obvious difficulty of trying to figure out why something has not occurred.

Yet the reality is that al-Qaida has not disbanded. In fact, it has been quite active, killing people around the world. Yet during the intervening 31 months, it has not again attacked the United States, its sworn enemy.

One answer could be that the Bush administration’s conduct of the war on terror, which has become a whipping boy during this presidential campaign, might just be working.

Of course, the other approach would be to chalk the whole thing up to dumb luck — or assume that the bad guys are just biding their time.

The time and money — not to mention the news-media overkill — spent on historical hindsight by the 9-11 commission is worthwhile because it is aimed at understanding why the system in place was unable to prevent the tragedy.

Yet it is just as important to think about the present and what the lack of a repeat incident says about the future.

Obviously, a similar public investigation into why nothing has happened would be impractical, given the hypothetical nature of the whole exercise.

But it is something all Americans should think about in deciding how they want to fight the war on terrorism.

Since 9-11, we have faced countless alerts about the possibility of the next terrorist incident. Public opinion polls show a widespread public belief that the next domestic attack is just around the corner.

But that has been the case for more than two years and, thankfully, nothing has happened.

There are two explanations — or a combination of them — that might explain the lack, thus far, of another terrorist attack within the United States:

l The U.S. government is doing a better job of deterring the terrorists.

l Al-Qaida may have decided that the costs of pulling off another attack inside the United States would not be worth the political costs.

The period of national unity that followed 9-11 has long since ended, and the Bush administration’s war on terror has become a political football.

His critics have decried Bush’s unwillingness to accommodate U.S. policy against terrorism to the international opposition to his tactics.

Democratic presidential hopeful’s John Kerry’s critique of the Bush doctrine boils down to the fact that it doesn’t give enough weight to world opinion in formulating U.S. policy.

On the domestic front, the Patriot Act, pushed through by Bush after 9-11 to give officials the necessary tools to combat terrorism here at home, has become a flash point.

Criticism that the act unnecessarily subverts civil liberties that was initially confined to fringe groups like the ACLU is now part of the Kerry mantra, even though he and most Democratic lawmakers voted for it.

Is it possible that the extra powers that law has given authorities have allowed them to prevent other potential attacks? Or perhaps it signals a stepped-up vigilance here at home that has led Osama and the boys to decide it is safer for them to blow up people in Spain and Bali.

Maybe the wars in Iraq and Afghanistan have tied up al-Qaida’s fighters and money and left them unable to focus on U.S. domestic targets.

Or maybe there is another explanation. Perhaps al-Qaida has decided it would be contrary to its self-interest to strike again in the United States, especially before November.

Such an attack would almost certainly re-create a sense of national unity that followed 9-11. Politically, it would likely create a rally-round-the-president effect.

Sure, the March 11 terrorist attack in Spain days before its presidential election led to the defeat of the party of the Spanish leader who had been a Bush ally in the war on terror.

But even terrorists who despise our culture are smart enough to understand how much more aggressive and confrontational (not to mention stronger militarily) we are than the Europeans.

The last thing al-Qaida would like is for Bush to be re-elected. My money says U.S. voters would react to attempts to scare them into voting for John Kerry by raising their middle finger to the terrorists, not surrendering like the Spanish.

As we play the blame game for 9-11, it’s worth pondering what the absence of a reoccurrence tells us.

Peter A. Brown is a columnist for the Orlando Sentinel.