Competing for the most bizarre suggestion of year is the Army War College study that proposes a division of labor between the regular Army and the Army National Guard, which gives the regular Army responsibility for the big conventional ground war and the Army National Guard responsibility for Counter-insurgency—or, COIN, in military lingo. Clearly, the study authors do not want United States involved in another COIN, fight like those we fought recently in Iraq and Afghanistan. Yes, we did call up National Guard forces tens of thousands of themfor those fights, but only when it was clear that the regular Army was over extended by the manpower requirements. Imagine the political trauma of calling out the Guard in sufficient numbers for a big push against ISIL insurgents in Iraq, and the fight in Syria while the Army stays home.

The assignment of big conventional war to the Army is also strange, given that (aside from nuclear war) the big conventional fight with a peer power is the least likely conflict we face. Sure we might get upset over trade disputes with China or islands in the South China Sea, but we are unlikely to invade mainland Asia as a result. Russia may invade the Baltic nations provoking a war with NATO, and thus us, but that possibility remains remote as well. To fight a peer, we need a big Army, but that Army would be in garrison mostly waiting for a bell that wouldn’t ring.

A better division of labor would give COIN to the Special Operations Commandessentially another armed servicewith backup from the Marine Corps and the Army. The Marine Corps would be around, as it is now, to save people from earthquakes and floods and to push around small nations. The Army National Guard, as some have suggested, is best a mobilization base for the big war. It should have lots of tanks and attack helicopters, and the opportunity to move to training for six months or more, once we are convinced that a big conventional war is on its way. For surprise attacks by big powers there is always nuclear war, or a package of World War Two films and histories that demonstrate the futility of trying to out-mobilize the United States.

The question then is what to do with the Army, our fifth wheel. The Navy and the Air Force are there to protect the frontiers and to punish distant enemies. The Marine Corps is the 911 force, responding to crises. Special Operations gets the COIN and anti-terror fights. The Guard is the mobilization force. And the Army is a little bit of everything. It is the structure for managing the big fight, supporting long wars, and being around for disasters of all types. It is there to occupy countries we should know better not to occupy. A clear mission? Perhaps not. Glamor jobs? Certainly not. The Army does everything, growing and shrinking with the tides of history.