The low, flat tone of the Shabbat horn was a familiar sound on a recent Friday afternoon in Jerusalem. Time to enter the Sabbath rest! Minutes later, however, residents of the capital city were surprised to hear a second horn – this one higher-pitched and disturbingly urgent. After a moment of hesitation, everyone realized it was warning of incoming rockets from Gaza.For the first time since the 1991 Gulf War, air raid sirens in Jerusalem were sounding a real alert. Hamas had targeted the holy city. Time to find shelter! For households all across town, the siren was a shocking wake-up call. Half of Israel is now within range of the terror militias in Gaza. But even more shocking was the sound that followed – fireworks, hours of them, set off just blocks away by east Jerusalem Arabs celebrating the bombing of their own city.Never mind that the rocket had landed in an Arab village east of Bethlehem, shattering windows in nearby homes. For these Jerusalem Arabs, it was time to dance in the streets and hand out sweets in solidarity with the thugs of Hamas.Parsons is media director for the International Christian Embassy Jerusalem; www.icej.orgAnd that should be an even greater wakeup call for all of us.Western apologists for Islam insist it is a religion of peace and that only a small number – 10 percent at most – are radical Muslims bent on our destruction. But the truth is radical Islamists have a lot of fans like these ordinary Jerusalem Arabs, content to sit on the sidelines and root for those actively engaged in jihad against Israel and the West. But if the radicals ever seize the momentum and start winning, the fans are going to pour out of the bleachers and join the fight.Right now, there are three main champions vying to win their loyalty.There are the radical Salafists led by al- Qaida, the more mainstream Muslim Brotherhood now in charge in Egypt, and the Shi’ite clerics in Iran. All three share the dream of one day reaching the promised “Golden Age of Islam,” when Muslims will finally rule the entire world and place it under the dictates of Shari’a law. But each champion wants to be the one that leads the rest of the Muslim world into that blessed age. And each espouses different paths for getting there – all of which must pass through Jerusalem.In this twisted competition for Muslim hearts and minds, the Salafists preach “Jihad Now” – a puritanical form of Islam that tolerates only what was taught and practiced by Muhammad and his closest companions. They know that Muslim veneration of Jerusalem is a later hadith (tradition), and thus they reject it. Yet they also know the hadith prophesying a final, end-time battle between Muslims and Jews will be centered on this city.Most of their fellow Sunnis are closer right now to the Muslim Brotherhood, which takes a more patient, measured approach. They seek to prepare the ummah (Muslim community) through education for the day when the caliphate is restored, providing the proper vehicle needed to conquer the world and impose Shari’a law. The Arab Spring has opened the door for this stream of radical Islam to seize the reins in Cairo, Tunis and elsewhere. But the Salafists are breathing down their necks, urging the Muslim Brotherhood to do more with their new found power.Meanwhile, the ayatollahs in Tehran await the coming of the Mahdi, a mythical messianic figure who will lead the world out of a great apocalyptic battle focused around Jerusalem and into the desired Golden Age of Islam. But they face a dilemma, as Shi’ites constitute only 15% of the Muslim world. So they want to leapfrog ahead of their larger Sunni rivals by acquiring nuclear weapons. These nukes will ensure not only that the Jews are wiped out in the apocalypse, but that the Shi’ites will be the ones leading the Muslim world into that Golden Age.The sinister competition between these three brands of radical Islam is extremely unhealthy for Israel and for the world.But for all those millions of moderate Muslims out there, they always seem to have plenty of fireworks and candy on hand for whoever is striking a blow at the infidels.