From the streets of Ramallah to the caves of Afghanistan, terrorists around the world were celebrating this week, as they commemorate the anniversary of not just one - but two - of their biggest coups against Israel and the West.
They set a chilling new standard for international terrorism, both in terms of the audacity of their assault, as well as the insolence of their aim: to undermine the very pillars of Western civilization. For that alone, Bin-Laden and his cohorts have earned a central place in the annals of infamy.
But September 11 is not the only significant occasion appearing on the terrorists' calendar this week.
There is another date as well, one that embodies just how crafty the practitioners of terror have become. It is 9/13, the date on which Yasser Arafat stood on the White House Lawn 13 years ago and signed the Oslo Accords, professing peace even as he was pursuing war.
With just a pen and a smile, Arafat succeeded in fooling the government of Israel and much of the West into believing that he had cast aside his boundless hatred and replaced it with a newfound yearning for reconciliation and peace.
Arafat's ultimate goal, as the ongoing Palestinian terror campaign has amply demonstrated, was no less lethal nor depraved than that of his Saudi-born colleague: to kill as many people as possible, all in the hopes of bringing his foes to their knees.
Though different in form and in substance, 9/11 and 9/13 do share one important trait in common: they both exemplify the danger of Western inaction when confronting an implacable enemy.
Remember: 9/11 was the second, not the first, attempt to blow up the World Trade Center in Manhattan. In 1993, a truck bomb exploded underneath one of the towers, killing six Americans. Had the Clinton Administration reacted as it should have, and launched its own war on terror, had it hunted down the perpetrators and refused to rest until Osama Bin-Laden was behind bars, who knows how much pain and suffering and even death might later have been averted?
Once Bin-Laden had joined the ranks of international terrorists, he should have been treated accordingly. But the sad fact is that he wasn't, and on 9/11, we all learned just how shortsighted and deadly that decision proved to be.
The same can be said for Israel's willingness in 1993 to sign an accord with Yasser Arafat, treating him as a lofty statesman rather than a lowly killer. Brushing aside three decades of PLO terror, the government of Israel handed Arafat the keys to Judea, Samaria and Gaza, and allowed him to create a corrupt, authoritarian terrorist entity straddling the Jewish state's narrow boundaries.
It was a sad exercise in self-delusion. The desire to appease the enemy led Israel's leaders to think that yesterday's murderer could serve as today's peace-partner.
Instead, had Israel acted as it should have, arresting Arafat and trying him for murder, rather than transforming him into a head of state, who knows how much turmoil and bloodshed might have been prevented?
All told, over 1,000 Israelis have been killed by Palestinian terrorists since the signing of the Oslo Accords, which is nearly twice the number that were killed in the 25 years that preceded the agreement. Clearly, the decision to accommodate Palestinian terror, rather than eliminate it, has proven to be a grave and fateful error on Israel's part.
The lesson, then, of this week's two anniversaries should be clear: the only way to get rid of terrorism is to get rid of the terrorists.
Apathy and appeasement may buy a few years of quiet. But in the end, the price of refusing to respond forcefully to terror is, inevitably, still more terror, and on a much larger scale.
With a little more foresight, and a lot more courage, the events of 9/11 and 9/13, and the destruction that was wrought as a result, might never have come to pass.
Let us hope and pray that Washington and Jerusalem will at last act to ensure that they never again recur.