Al Qaeda in Iraq knew they could not defeat the United States on the battlefield so they planned to defeat the U.S. at home. In 1968, the communists in Vietnam threw themselves against the U.S. Military with all they had in the Tet Offensive. They were defeated and utterly destroyed. The media, however, convinced the American people that the communists were strong and Walter Cronkite told the world the war was unwinnable. A desperate, suicidal offensive that ended in military failure became the path to victory for the communists. They defeated America on the homefront, not on the battlefield.
This was not lost on al Qeada in Iraq (AQI) and the Iranians. They saw the way in which Tet won the war for the communists and planned to emulate it. AQI, however, was even weaker than the communists in Vietnam. Instead of a direct assault on the military, they would begin killing hundreds of Iraqis to create a managed “civil war” in Iraq. It was all stagecraft for the benefit of the Western media and the Democrats in the U.S. If they could convince Americans that Iraq was a civil war and unwinnable, they would force the U.S. Military to withdraw.
The “civil war” characterization of the war was a force multiplier for the al Qaeda/Democrat media war alliance. “Continuing violence” by itself did not by itself have a very powerful anti-war effect because it had tendencies not just to depress America’s fight spirit, but also to energize it. If the violence showed al Qaeda waging war on the Iraqi people, that would show the American people and the Iraqi people on the same side, which would make Americans want to protect Iraqis, while hinting at the reality on the ground: that more and more Iraqis were turning against al Qaeda.
Of course, AQI and the Iranians knew their time was limited. The more Iraqis they slaughtered, the the more the Iraqis turned against them. It is one thing to convince the American public that the violence was Iraqi-on-Iraqi, but the Iraqis knew better. With each week of violence, more more Sunnis turned on AQI and more Shia turned on the Iranians. It was a race. Could AQI and the Iranians convince the Democrats and the American people the civil war hoax was reality and goad them into surrender before 100% of the Iraqi people turned on them? The media and the Democrats played “useful idiot” to al Qaeda and the AQI plan was within grasp of victory.
Enter General Petraeus and the Surge.
Alec Rawls at Error Theory has the whole article and all the details. You really need to read the whole thing.