Thousands of Muslims who say they are ready for martyrdom have flocked to Iraq since the U.S.-led war began, a sign that a prolonged stay of U.S. and British forces may turn the country into a magnet for militants seeking a new jihad.
On Saturday, a suicide bombing the hallmark of Muslim extremism killed four U.S. soldiers near the holy Muslim Shiite town of Najaf south of Baghdad in the first such attack on allied troops since the war began March 18.
Iraq vice president Taha Yassin Ramadan threatened more, saying suicide bombings would become "routine military policy."
"We will use any means to kill our enemy on our land ... the Iraqi people have a legal right to use any means to deal with the enemy," he said.
Iraqi leader Saddam Hussein has recently begun to publicly link religion to his cause, peppering speeches with quotations from the Quran and reassuring Iraqis that God was on their side.
Iraq media has also been projecting heavy religious undertones, calling army troops "soldiers of God" and Arab rulers allied with the United States "infidels and atheists."
At a Saturday news conference, Ramadan refused to say whether Iraq will accept assistance from Osama bin Laden, whose al-Qaida terrorist group is blamed for the Sept. 11 attacks. He asserted that Iraq would support anyone willing to stand up to U.S. and British forces until they leave.
Thousands of Arab volunteers seeking martyrdom were flocking into Iraq and more were expected, he said. He would not give exact numbers, but Iraq's state television later estimated 4,000 people had arrived.
Ramadan said Iraq would supply the volunteers with whatever they needed to help fight the thousands of U.S. and British forces in the country.
"If there is an American occupation, then Iraq will definitely move to the top of the list of jihad for the international network of Islamists," said John Voll, an Islamic affairs expert at Georgetown University.
Iraq earlier this month publicized one of its battlefield tactics when it took foreign journalists to a training camp east of Baghdad to show off about 40 of what it said were Arab volunteers.
The men bore all the hallmarks of Muslim militants. Most wore beards, chanted slogans glorifying holy war, voiced deep hatred for America and said they would seek martyrdom on the battlefield.
Wearing uniforms and headscarves, they prayed together, listened to a rousing sermon on jihad and chanted slogans vowing death for America and Israel. They said they came from Algeria, Libya, Tunisia, Egypt, Syria and Saudi Arabia.
"I came (to) offer my life for the sake of the Arab nation and Iraq," said a Palestinian who would not give his name. "We came as part of a martyrdom project against the Americans."
Thousands of Muslims from across the world joined the Afghan mujahedeen in their fight against Russia's occupation army in the 1980s. After driving the Russians out, some stayed, some returned home, while others emboldened by their victory over a superpower went on to continue the fight in other trouble spots like the Balkans and Chechnya.
More recently, the U.S. military campaign against Afghanistan's Taliban government lured a ragtag army of thousands, mainly from neighboring Pakistan, vowing jihad against the Americans.
Magnus Ranstorp, a terrorism expert at the University of St. Andrews, Scotland, said most jihad fighters are focused on Chechnya, which he called "today's Afghanistan."
"Iraq also can become another Afghanistan, but with a huge twist because of the different regional factors," he said.
Dia'a Rashwan, a prominent expert on radical Muslim groups, views an Iraq occupied by the U.S. military as the "perfect" environment for Muslim militants seething over what they see as Washington's war against Islam.
"With so many American troops required to occupy Iraq, they'll be like hostages," he said.