There is a grim inevitability to the latest wave of suicide car bombings, assassinations and other attacks in Iraq and a dire conclusion can no longer be avoided. The United States now has a Battle of Algiers on its hands in Baghdad.

It is very likely that veteran jihadi, or holy warrior Islamic extremists from outside Iraq, are now applying their expertise in recruiting, training and organizing suicide bombers, especially in ambitious operations like the assassinations of UN special envoy Sergio Vieira de Mello and of Shiite Ayatollah Mohammed Baqr al-Hakim in August.

It is also very likely that veteran Ba'athists, especially Special Republican Guards veterans, who quietly dissolved their units and slipped away during the misleadingly rapid three week military conquest of Iraq in March and April are involved in many of the hundreds of attacks on U.S. troops in their country, now running at rates of 20 to 35 such assaults a day.

And it is certainly true that there are plenty of places in Iraq, especially around the countryside, where things are a lot quieter than in Baghdad, as administration spokesmen and apologists claim.   But none of those things, nor the limited but real success of the administration in getting international donors to pony up several billion dollars for reconstruction at the Madrid conference can alter a central fact: a full-scale guerrilla war against U.S. and Western forces in Iraq is now fully underway, and it has already reached formidable proportions.

The attacks are by no means limited to Baghdad or even only to major cities. And U.S. and British military analysts have told UPI they cannot be all blamed on old Iraqi Baathists or foreign jihadi troublemakers either.   On the contrary, these professional military experts are explicit that the overall pattern of violence clearly shows a widespread, popular revolt with a high degree of decentralization and local initiative. The resistance is rapidly evolving and organizing, they say, but it is organizing from the bottom up rather than from the top down.

And for all the problems the U.S. occupation problems now face in Basra, Falluja and around the country, their biggest headache is in Baghdad.   The attacks of this past week show that only half a year since the U.S. armed forces rolled into the Iraqi capital as unstoppable conquerors, they are facing a full-scale urban revolt as serious as anything the British Army faced in Belfast during a quarter century of urban conflict there from the riots of August 1969 to the Irish Republican Army cease-fire of 1994.

Indeed, in many respects, the security dilemma the U.S. Army now faces in Baghdad is far worse than anything the British and French faced in Belfast and Algiers.

Belfast had been a British city for all of its 300-year history before the new wave of "Troubles" began in August 1969. France had ruled and colonized Algiers for 120 years before the great and terrible FLN uprising began in 1954. Algiers, indeed, under French law was part of Metropolitan France.   In other words, the British and French armies knew the cities of Belfast and Algiers very well. And they could also count on large elements of the population being loyal and supportive of them. Two-thirds of Northern Ireland and Belfast's population were Protestant unionists. The IRA could only hope to count on support from people who were a minority even within the minority Catholic republican community.

In Algeria, the French army could count on the strong support of the pieds noir, the populist French immigrant colonist community and to the end of the eight-year war; they continued to enjoy loyal and strong support from large elements of the Muslim majority. After Algerian independence, hundreds of thousands of these people were massacred, along with their families, by the victorious FLN forces.

But in Baghdad, the United States has no prior history, experience or associations whatsoever. And proportionately, it even has far fewer troops on the ground than the British did in Northern Ireland or the French, with their great conscript army, did in Algeria.

At the height of the Northern Ireland Troubles, Britain had to flood the tiny province of 1.5 million people with 35,000 troops. And the security threat they had to contain came only from unrepresentative elements within a community of half a million people.   Even if the guerrilla violence in Iraq gets no worse than Northern Ireland was -- and in fact it already has -- that would require around 600,000 U.S. and allied troops compared to the around 160,000 British and U.S. ones in the country today. And even that would be on the assumption that Iraq's majority 15 million Shiites stay entirely on the sidelines: an assumption that is looking increasingly uncertain.

Also, Baghdad is a vastly larger and more populous city with at least 15 times more people than either Belfast or Algiers had during their worst years of guerrilla-terror insurgency.  In their wave of coordinated suicide bomb attacks in a single day this past week, the guerrilla forces in Baghdad showed a capability and ruthlessness comparable to that of the National Liberation Front, or FLN, during the frightful Battle of Algiers in the 1950s and the early 1960s, arguably the most horrific of all modern urban guerrilla wars.

Back in August, after the bombing assassinations of UN envoy Vieira de Mello and Ayatollah Baqr al-Hakim, we concluded in UPI Analysis, "Not only does the United States have a wolf by the ears in Iraq, but the muzzle is off and the wolf has learned how to bite. Fast." Today the wolf is bigger than ever and growing by the day, and its appetite for violence is growing too.

Martin Sieff is chief news analyst for United Press International.  This adapted piece is used with the permission of UPI.