Similar campaigns were fought in Egypt and Algeria during the 1990s. The Egyptians defeated the Moslem Brotherhood (and the survivors fled to help found al Qaeda). Algeria finally defeated a similar movement only in the past year, the Egyptian campaign took most of the decade. Syria crushed the Moslem Brotherhood in the early 1980s, after five years of violence. These three Arab nations are all police states, and were able to deploy large numbers of police and soldiers that spoke the same language as the terrorists. Israel also had a large number of terrorists who spoke Arabic. Many had grown up in Arab countries, or had parents who had done so. What all these successful campaigns had in common was aggressive tactics that took the battle to the enemy. Treating terrorism as if it were just a police matter, allowed the terrorists to continue building support, and the ability to launch more attacks. By going into the terrorist neighborhoods, you disrupted their planning and recruiting efforts, and eventually destroyed the network of support. The United States clung to the police approach throughout the 1990s, and the attacks continued. Only after September 11, 2001, was the war carried to the terrorist heartland, and the attacks in the U.S., and against American targets elsewhere, ceased. The terrorists were forced to defend their base, and in doing so they killed many Moslems, and turned Moslem public opinion against them.
Without a secure base to operate from, the terrorists threat was much diminished. This is why al Qaeda has made so few attacks in the lands of their enemies. In the United States, nearly two decades of trying has resulted in only two attacks (1993 and 2001). France got hit with several attacks in the 1990s, as a byproduct of the Islamic terrorism in Algeria, but have shut down the terrorists since. The rest of Europe has been hit twice (Madrid last year, and London recently) since September 11, 2001. Not a lot to show for an "international terrorist organization," with "millions of members and supporters."
The war in Iraq and Afghanistan has taken the battle to the heart of those regions that supply the leaders, and foot soldiers, for Islamic terrorism. In Iraq, this revived a civil war that had been flaring up periodically for decades. This time, the Sunni Arab minority were not able to crush the Kurds and Shia Arabs who comprise 80 percent of the population. Aided by Islamic radicals who want to establish a religious dictatorship, the Sunni Arabs have been losing rather visibly. The towns and neighborhoods where the Sunni Arabs could operate openly have been shrinking over the last year. Over the last few months, the number of terror attacks has gone down as well.
On a wider scale, the Islamic terrorism is a response to tyranny and self-delusion in the Arab world. Islamic terrorists fight the former, and embrace the latter. But both the acceptance of tyranny, and fondness for self-delusion, are still problems in the Moslem, especially the Arab, world. Until those two self-defeating habits are overcome, unrest in the Moslem world will continue. The invasion of Iraq kick started the process, removing the local tyrant, and forcing all Iraqis to confront the delusions that have led them to defeat after defeat over the last half century. The Islamic terrorists can be beaten down in the short term. That's been done a lot of late. But unless the bad habits are changed, the terrorists will keep coming back.
Who's won against terrorists lately? In the last decade there have been several terrorist campaigns that were defeated, all of them involving Islamic radicals. Most recently, there was the Palestinian terror campaign against Israel. The Palestinian terrorist groups still say they are going to destroy Israel. But as a practical matter, the current round of Palestinian terrorist violence is over. You can see this by the sharp decline in successful terrorist attacks, and the frequent pronouncements from the terrorists groups that they are going to behave, for a while anyway. What the terrorists really want is to avoid anymore of the Israeli tactics that shot down their terrorist operations. This included going after terrorist leaders and technical specialists, and either capturing or (failing that) killing them. Raids and air attacks were made against buildings used by the terrorists, and tight security on Israelis borders were instituted. This least measure crushed the Palestinian economy, which put popular pressure on the terrorists to stop their attacks, and promise to keep it that way. The Israelis also set up an increasingly effective intelligence system inside Palestinian territories. What the Israelis did was "take the war to the enemy." This is an application of the old maxim, "the best defense is a good offense." This particular war went on for six years, but the Israelis only adopted their winning tactics two years ago.