Someone in the Pentagon, speaking on background (which is a pretty crowded place, these days) has let the world, and our enemies, know when and where the offensive is coming. According to the New York Times, “The assault to retake Mosul, Iraq, from the Islamic State will require 20,000 to 25,000 Iraqi and Kurdish troops and is expected to begin in April or May, an official from the United States Central Command told reporters on Thursday.”
This seems, on first reflection, an unusual way to wage war. A violation, certainly, of Sun Tzu’s insight that, “All warfare is based on deception. Hence, when able to attack, we must seem unable; when using our forces, we must seem inactive; when we are near, we must make the enemy believe we are far away; when far away, we must make him believe we are near.” Or, if you prefer something closer to home and in the American idiom, Stonewall Jackson’s rule that a general should “Always mystify, mislead, and surprise the enemy, if possible …”
As to the coming offensive in Irag, the Pentagon source has let the enemy know where, when, and with what, telling reporters, according to the Times that
…the main Iraqi attack force would consist of five brigades, each of which would number about 2,000 troops.
The Iraqis will keep three smaller brigades in reserve. Three brigades of Kurdish pesh merga fighters will also join the fight to contain the Islamic State militants from the north and maneuver to cut off approaches to the city from the west.
There isn’t much left after that, unless there is some secret weapon which will be deployed by the attackers, some modern variation of the longbow at Agincourt.
One looks to history for reassurance, for a hint there might be more here than the Pentagon is letting on. Perhaps this is not a repeat of the Somme, where the British armies went about their preparations for months in plain view by the enemy who took the appropriate measures and were ready when the time came.
Perhaps, one thinks, it is all a ruse for which there is a sovereign place in the history of war. Make your enemy think you are about to strike the obvious target, lure him into extensive preparations there, then strike some other target that has been weakened by these very measures. General Norman Schwarzkopf had the Iraqi army looking to its left in the first Gulf War, convinced that the Marines would be making an amphibious assault there. Coalition forces, instead, hit with the famous “left hook.”
But the greatest such deception in modern American military history took place in World War Two, with the creation of something called FUSAG. One can imagine the fun that troops had with parsing that acronym but what it stood for, in truth, was the First U.S. Army Group. Which was a fiction.
FUSAG was created to lure the German command, including Hitler, into believing that when the Allied armies came across the English Channel in the spring of 1944, they would be landing at Pas-de-Calais.
Adding to the plausibility of the ruse was the fact that a crossing there would have been where the English Channel is narrowest. Also, seizing that objective would have provided the Allies with a port though which they could offload and move the thousands of tons of supplies necessary to support the invasion.
A landing at Normandy, the actual target, meant a longer crossing and the necessity for bringing supplies through the surf and across the beach once it had been secured. The crossing, as it turned out, was amply covered from the air and the Allies were able to turn the Normandy site into an ad hoc harbor though the expedient of sinking ships around it to provide a breakwater.
Now to convince the Germans that the Allies would be landing where military logic said they would -- this took planning and imagination.