For those seriously interested in the question I recommend a seriously interesting new book, America's Secret War by George Friedman. Friedman is founder of Stratfor, a private, subscription-financed global intelligence service, which I find consistently well-informed. Friedman writes of the struggle in Iraq in relentlessly Realpolitik terms.
Although the US believed Saddam Hussein possessed weapons of mass destruction, the WMDs were ultimately "a cover for a much deeper game". The big game began with the Soviet Union's invasion of Afghanistan and the US enlisting the assistance of Saudi Arabia in backing the Afghan resistance. The Saudis provided financing and guerilla fighters. They influenced other Islamic countries to send guerillas.
This international brigade included members of Islam's moneyed and educated elite (including Osama bin Laden) - the core of al-Qa'ida.
When the Soviet Union retreated from Afghanistan, this elite had become knowledgeable veterans of guerilla warfare, full of swagger about defeating the world's second superpower.
The oil billionaires back home, impressed with themselves for "bailing the Americans out", financed the warrior elite and the fundamentalist Taliban regime in Afghanistan.
From this fortress headquarters, Friedman writes, al-Qa'ida ("the Base" in English) pressed its grand design for an Islamist world federation, a new Caliphate, which would ultimately match, if not dominate, other superpowers. Global terrorism would be the means. Al-Qa'ida's opening moves - attacks on American embassies and other establishments abroad - were aimed, in Friedman's opinion, less at damaging the US than provoking it to a reckless assault on Islam.
This, al-Qa'ida believed, would stir the "Islamic street" to a confrontational mood with the West and rebellion against non-fundamentalist Islamic regimes, establishing the foundations of the great federation. Following the collapse of the Soviet Union, however, the US, confident of its hegemony, had concluded that "war was now optional", that no power existed that could force it into war.
The passive US response to its early pinprick attacks emboldened and frustrated al-Qa'ida. The jihadists, Friedman writes, "needed to strike a blow that would be devastating, [breaching] the threshold between what was tolerable and intolerable for the US". Their initiative was the September11, 2001, attack on New York and Washington, which shocked and disoriented the Americans. Their first reaction was to speculate almost in panic about a September 11 with nuclear weapons.
This began an obsession with WMDs. US actions were practical and reasonably prompt, however. The US persuaded Russia and other countries of the former Soviet Union to make inventory of their nuclear weapons and strengthen security on them.
Rather astonishingly, as Friedman reports it, the US pressured Pakistan - the Muslim country most advanced in nuclear weaponry and the one in closest contact with Islamic fundamentalism - into permitting US soldiers dressed as civilians to place a guard on its nuclear stockpile. To disabuse Islam of the illusion that the US was weak of will and, on the evidence of Vietnam, unable to sustain a prolonged war, the Bush administration decided to strike its own devastating blow in response to September 11.
The invasion and speedy subjugation of Afghanistan staggered the jihadists. But the US, having succeeded only in dispersing al-Qa'ida and the Taliban, rather than eliminating them, believed it needed to strike another heavy blow.
By then it had identified the jihadist campaign as "a Saudi problem". Most of the September 11 suicide attackers had been Saudis. Bin Laden was a Saudi. Saudi money trails were everywhere. An invasion of Saudi Arabia presented the tactical problem of waging war against a country of vast area and the strategic one of disrupting the world's oil supplies.
The Americans had established and then strengthened a military presence in countries surrounding Saudi Arabia - Yemen, Oman, Qatar, Bahrain and Kuwait. Invasion of Iraq would complete the encirclement.
"From a purely military view," Friedman adds, "Iraq is the most strategic single country in the Middle East, [bordering] six other countries: Kuwait, Saudi Arabia, Jordan, Syria, Turkey and Iran."
So the US struck, with consequences unfolding nightly on our TV screens. Friedman believes the US-jihadist war hangs in the balance. However, the measured actions of the US during the past three years, including its strong military presence in the Middle East, have caused significant moderation of the position on global jihad of Saudi Arabia and other Muslim regimes.
The strategy of the jihadists has stalled: "Not a single regime has fallen to al-Qa'ida ... There is no rising in the Islamic street. [There has been] complete failure of al-Qa'ida to generate the political response they were seeking ... At this point the US is winning ... The war goes on."