“an army marches on its stomach”

WSJ.com – U.S. Tactics May Seem Original, But History Offers Some Lessons

HISTORY LESSONS
Key elements of the U.S. war plan in Iraq have been tried in earlier wars, to mixed results.

• Bypassing population centers in a rush: Confederate Gen. Stonewall Jackson did the same in his 1862 Civil War campaign in the Shenandoah Valley, leading to early successes.

• Long supply lines: They became a significant problem when Germans invaded Russia in World War II.

• Guerrilla warfare: Iraqis may be borrowing tactics that worked for fighters opposing Israel in Lebanon and the West Bank and Gaza Strip over the last 20 years.

• ‘Shock and Awe’: A much more extreme version — atomic bombs dropped on Hiroshima and Nagasaki in 1945 — helped bring World War II to a successful end for American forces.

Napoleon said it best.

So we have underestimation of how hard the enemy would fight off an invasion and classic supply line management problems. The armchair generals are not looking so clever.