The planners of this war considered a range of scenarios. At the most optimistic, they hoped that the imminent threat of invasion would trigger the collapse of Saddam Hussein's regime. At the next rosiest level, they thought a regime collapse would follow an invasion in a matter of days. On the next rung was the idea that the American advance would be met by little armed resistance, which would allow for a swift advance and a possibly hard but brief battle with the Republican Guard's Medina Division south of Baghdad.
What actually happened in the first five days was a surprise and made the American advance significantly more difficult and dangerous. In large terms the plan has worked and the attack to date is an overwhelming success. The 3rd Infantry, which leads the assault, advanced more than 185 miles into Iraq in three days. It defeated the Iraqi 11th Division in one day with no American casualties. It established a supply line over forbidding terrain back into Kuwait that is supplying a fast-moving force of more than 20,000 soldiers and 10,000 vehicles.
But something else transpired. While Hussein's regular army has scarcely fought at all, an irregular force controlled by the Baath Party of militia, elements of special units and Fedayeen guerrilla fighters has conducted a campaign of small-arms hit-and-run warfare. These forces have essentially taken control of the southern cities of Samawah and Najaf, where they have established themselves in schools and hospitals and where they are reportedly forcing local men to arm and fight by executing the unwilling.