Against the relentless menace of Islamist terrorism, Westerners need to find a middle ground between a state of permanent - and unsustainable - high-alert, and the reckless attitude of "What, me worry?" The days when travelers could journey by air without fear of their planes being hijacked are history. So, too, are the days when Israeli authorities could reasonably think that removing security checkpoints in Judea and Samaria would have no fatal consequences. First the West Bank: The security services are to be commended for an outstanding operation Saturday which liquidated three Fatah terrorists responsible for last Thursday's drive-by murder of Avshalom Chai, a 45-year-old kindergarten teacher and father of seven. One of Chai's killers had been released recently from an Israeli prison; another had promised to eschew terror in return for amnesty. The killers were tracked to two dwellings in Nablus's Old City, part of a larger sector under Palestinian security control. The cell may have been Hizbullah-run, or overseen by extremist Fatah leaders, or may have acted autonomously. We know only that ballistic tests connected the three to the Chai shooting. The European-funded advocacy group B'Tselem criticized Israel's failure to take the hardened terrorists alive. But from the data available, we believe that Israeli forces - operating for hours in a hostile environment - acted prudently. We note that B'Tselem did condemn the murder of Chai by reiterating its view that deliberate attacks against civilians are a war crime. It's hard to know whether reinstating the roadblocks in the greater Nablus area, which the government recently removed at the behest of the Obama administration, will prevent future attacks against Israeli motorists in the northern West Bank. Checkpoints cause inconvenience to Palestinian commuters by extending journey times. But there is often no way to intercept terrorists without inconveniencing the general public - not on a northern West Bank road and not at international airports. Those who defend freedom must make it hard for terrorists to disrupt the lives of innocents while minimizing the misery caused them in the process. ONE way to reduce inconvenience and increase security at busy airports is by a greater use of profiling. Farouk Abdulmutallab should not have been free to try and blow up Northwest Airlines Flight 253 with 289 people on board over Detroit on Christmas Day. Profiling would likely have identified the 23-year-old engineering student as a potential Islamist terrorist; he would have been methodically searched and stopped at Amsterdam's Schiphol Airport. Abdulmutallab, the privileged son of a banker, got his US visa in London in 2008. Family members told The Daily Telegraph that the bomber had been radicalized while a student in Britain. To his credit, Abdulmutallab's father recently warned American consular officials in Lagos that his son posed a danger. The young man was then placed on a catch-all anti-terrorism database, but not on the "no fly" blacklist that would have prevented him from boarding any US-bound airliner. Mercifully, an alert passenger subdued Abdulmutallab just as he was igniting his explosive device. Those responsible for security in Lagos (which he may have reached from Yemen) and in Amsterdam (where he changed planes for Detroit) need to explain how they let him get on an airliner with a concealed syringe and the crystalline high explosive, pentaerythritol, sown into his underwear, reportedly, in a condom. IN response to the Abdulmutallab affair, US and European authorities are initiating more stringent and time-consuming searches of all passengers. Absurdly, travelers headed for the US may be required to remain seated during the final hour of their flights - no toilet - and will not be allowed to keep anything on their laps. Rather than adding profiling to security procedures, thereby identifying possible Islamist terrorists - protecting the rights of the many while infringing minimally on the rights of the very few - all passengers will be subjected to unnecessary, sometimes painful, inconvenience. The alternative to profiling is requiring all passengers to go through whole-body imaging scanners that can reveal objects beneath a person's clothes. But these devices are pricy and raise all sorts of civil liberties issues. Unless Western decisionmakers reverse course, their adamant and misguided refusal to utilize profiling will senselessly subject millions of air passengers to a form of collective punishment.