Key point: A separate Air Force actually makes it harder for land, sea, and air forces to work together.
With the Iraq War over and the fighting in Afghanistan winding down, why does the United States need to maintain two large land armies, the Army and Marine Corps? The question seems perfectly reasonable given the apparent absence of large terrestrial threats, but it leads us down the wrong path.
The United States military is all about redundancy; in addition to two armies, it also fields two navies — the Navy and the Coast Guard — and five or six air forces, depending on how you count the aerial arms of the various branches.
The real problem isn’t that the Army is marginally more or less useful that it was 10 years ago, but rather that the institutions that were designed in 1947, when the Army and Air Force split, are insufficiently flexible to negotiate the modern security landscape.
The fault for this lies not primarily with the Army, but with the United States Air Force, an institution built on the optimistic vision that ordnance delivered from the air could, cheaply and cleanly, bring about a peaceful, American-dominated world.
How to build a military branch
Look, creating institutions is all about drawing useful lines between areas of responsibility. Historically, it made sense to divide the responsibility between managing security on land and on sea between specific organizations tasked with training, managing and equipping professionals in their respective arenas.
In other words, an army and a navy. They had their disputes from time to time, but by and large their missions were sufficiently distinct — as distinct as earth and water, really — that differences in outlook, opinion, and interest didn’t interfere all that much with fighting actual wars.
But even from the dawn of flight, it never made much sense to separate the professional upbringing of aerial warfighters from their sea and land counterparts. Since before World War I, aviators have supported soldiers and sailors through reconnaissance, interdiction of enemy transit, air transport and direct attacks against fielded enemy forces.