A morbid thought whirled through my mind as I was lunching in a restaurant famed for hosting mainstream press and broadcast personalities: How do we prevent a suicide bomber yelling “Allahu Akbar” from bursting in and blasting us all to kingdom come?

Such thoughts occur to me whenever I’m on public transportation, in a crowd, or walking along streets shadowed by towering skyscrapers.

I don’t allow these negative images to stifle my lifestyle, but I do wonder how those on the left regard this ever-present threat to our security. Do they even consider how Herculean is the task necessary to completely thwart such catastrophes? Probably not. Only those New Yorkers who are keenly aware of the peril we all face harbor these awful possibilities in our everyday thoughts.

Seated behind me was a famous gossip columnist. Across from me was a former secretary of state who was chatting with a former head of Planned Parenthood. To my left sat an anchorwoman for a network newsmagazine. Aside from my companion, I was the ideological opposite of this luncheon crowd.

Some of these individuals have been quite vocal in their opposition to the war in Iraq and our president. They’ve mouthed only platitudinous support for our brave military men and women, who have been putting their lives on the line so that we all might dine in peace. They certainly will not credit the leadership of President Bush for the fact that we have not been attacked on American soil since September 11, 2001.

Instead, they have been steadfast in their criticism of the Patriot Act, domestic surveillance, and other anti-terrorism security measures. I would have much more respect for their opinions if I knew what their answer was to the big question: How do you prevent another September 11?

I went to the liberal Web site moveon.org to look for the left wing response to that question. I found plenty of suggestions and comments about getting out of Iraq; censuring Mr. Bush; not attacking Iran; the evils of “domestic wiretapping”; boycotting Exxon; protecting Social Security, and election tactics – but no viable plan to stop terrorism.

Liberals endorsed Senator Kerry for president in 2004. His entire anti-terrorism plan was one of defense, of preparing for another attack, not preventing it. Our current plan is one of offense, and it has worked well for the past five years – at great cost. It might have been even more successful were it not for some of those people in the restaurant and the anti-war hordes. They’ve given aid and comfort to an enemy who is determined to kill us all.

Last Saturday, thousands of anti-war protesters marched through the streets of Lower Manhattan on a sunny spring day carrying signs that read ” Bush is worse than Bin Laden.” I’m at a loss to understand such blind ignorance, but the writers of Comedy Central’s irreverent “South Park” captured the inanity perfectly in a recent absolutely brilliant episode.

In “The Cartoon Wars,” the entire town is so terrified that jihadists will be provoked to violence by a television show depicting a cartoon of their prophet that the townspeople agree to literally hide their heads in the sand. That way, they reason, they won’t be attacked. The “South Park” denizens aren’t any less ridiculous than those marchers who actually believe that Thomas Jefferson said, “Dissent is the greatest form of patriotism.” He never did. Mr. Kerry said he did, and the gullible believed him.

Please tell me, Susan Sarandon, Al Sharpton, Cindy Sheehan, or anyone else demonstrating against the war: What is your brilliant plan to prevent more terrorism from striking at the heart of this city? Face it – you have none.

I, too, have complaints about the war, but they’re about how it’s being waged. If anything, we’ve been too humane. Our military was so concerned on the march to Baghdad, Iraq, about civilian casualties that it allowed Saddam’s killing squads to escape into the civilian population, where they’ve reemerged as euphemistically titled “insurgents.”

These killers are bolstered and sustained in their murderous attacks by foolish American protesters who are more appalled by Abu Ghraib “torture photos” – which, incidentally, are on the level of Eighth Avenue S&M sex videos – than on the graphic (and all too routine) beheadings committed by these barbarians.

If we had all maintained the sanity of those first months after September 11, when we recognized that the only way to prevent such a thing from happening again was to wage war against all terrorism, perhaps my fleeting morbid images would have disappeared by now. Alas, given the insanity of last Saturday, all I can do is mutter a silent plea to our president: “Stay the course, stay the course.”