In late 1998, national security officials under President Bill Clinton mulled a strike deep into Afghanistan that may have taken out Osama bin Laden. In the end, Clinton decided the potential cost of hundreds of innocent lives was too high.
No one can be sure that such a strike would have eliminated the al Qaeda terror chief, let alone forestalled the 9/11 terror attack three years later that cost the lives of 2,977 people, most of them Americans.
But Clinton and his military chiefs at the time, some of whom warned that holding back was a mistake, will always have to wonder, as will we all.
Will we face the same kind of hindsight in the future if, God forbid, the savages of ISIS (or ISIL, as the U.S. calls the radical terror group) is able to infiltrate our borders and carry out a large-scale attack here?
As we mark the 13th anniversary of the worst attack on America in history, Americans are worried about new carnage, with a recent NBC News poll finding that nearly half (47 percent) of respondents saying we are less safe now than before Sept. 11, 2001, up substantially from 28 percent last year and, amazingly, up from 20 percent just a year after the attacks on the World Trade Center and Pentagon.
Another poll by NBC and the Wall Street Journal founds 61 percent of Americans, nearly two out of three, support increased military action against the ISIS militants. No doubt they have been affected by videos showing mass executions in Syria, including children and the beheadings of American captives, and news of missing Libyan passenger jets likely commandeered by militants.
President Obama has an opportunity, and an obligation to reassure Americans. In his speech from the White House on Sept. 10, the president seemed to deviate between trivializing ISIS and beating the war drums. First he delegitimized its religious roots, noting that it has harmed mostly other Muslims and emphasizing that 'Islamic state' is recognized by no government.
Then, sounding more like the Republican predecessor that invaded Iraq and Afghanistan than the domestic-minded Democrat who vowed to wind down those wars, Obama vowed that "America will lead a broad coalition to roll back this terrorist threat" and warned that those who attempt to harm Americans "will find no safe haven." This is an echo of the Bush doctrine that America will not distinguish between terrorists and the governments that harbor them.
Ultimately the speech showed the president at his most determined, promising to "degrade and destroy" the capability of the militants and recognizing that "small groups of killers have the capacity to do great harm."
But are 475 new soldiers in Iraq on a non-combat mission, increased air strikes in Syria and more aid to the rebels fighting ISIS enough to accomplish those goals?
The president's ability to take executive action as commander in chief is limited, and he needs strong support from both houses of Congress, on both sides of the aisle, to fully prosecute the mission of neutralizing ISIS and its allies.
It's not at all clear that he'll get it from a war-weary and deeply partisan Congress. Many members will have to be convinced that arming rebels and minority groups resisting ISIS -- which is so extreme that al Qaeda distances itself -- is in our interest; others will fixate on blaming the president for failing to leave a sufficient interim force in Iraq, which could have stemmed the ISIS tide, or failing to back the rebels in Syria in toppling Bashar Assad.
Others will simply urge sitting on our hands. Voters will be influenced by commentators who note that as bad as doing nothing sounds, acting ineffectively, or counterproductively, is worse.
"Maybe it's time for America to stop taking the bait," says Fox News host and commentator John Stossel. "Islamic militants do monstrous things all over the world. We cannot stop it all. Why do we assume that government doing something is always an improvement over government doing nothing?"
Stossel noted that Clinton launched Tomahawk missiles at Osama Bin Laden, missed and was mocked as a paper tiger.
But the problem with inaction vs. action is that the result in the former case is almost guaranteed: ISIS will rise in popularity, adherents from all over the world, including the U.S., will continue traveling to the Middle East to join the fight or form terror cells in the West. The more we shirk away from our role as the world's leading policeman against terror, the likelier the possibility we will live to regret it.