We're far from potential theaters of war. Which means that the best combat corps in the world sitting in Fort Hood or Fort Campbell is useless if it can't get to the theater and be sustained in combat there.
Unfortunately, the dull stuff like moving troops has been shortchanged:
On May 2, U.S. Transportation Command commander Air Force General Darren McDew told the Senate Armed Services Committee that America doesn't have enough supply ships, transport planes and tanker planes to move a large combat force to a distant battlefield (like Korea) and sustain that force.
Honestly, I'm not too concerned about the problem of airlifting a non-light infantry brigade to South Korea from America. Quite some time ago I read that it would be a race between identical brigades being sealifted or airlifted to South Korea given the shortage of planes with other missions.
And as the article notes, there aren't many theaters where a single brigade will make a difference.
Russia is very close to Poland and the Baltic states, of course:
U.S. Defense Secretary Jim Mattis on Tuesday criticized what he called a destabilizing Russian military build-up near Baltic states and officials suggested the United States could deploy Patriot missiles in the region for NATO exercises in the summer.
U.S. allies are jittery ahead of [Zapad 2017] war games by Russia and Belarus in September that could involve up to 100,000 troops and include nuclear weapons training -- the biggest such exercise since 2013.
Russia by road and rail can outrace our troops going by sea and air (and then road and rail).
And we can hardly afford to commit the bulk of long-range Air Force airlift to one (pointless) airlift mission. Add in that affording that many airlift planes--and keeping the enemy from shooting them down--is problematic.
Right now we rotate a combat brigade to southern South Korea as a "tripwire" force. When I was in high school, if memory serves me, we had two divisions. And we parked a lot of our troops right on the DMZ north of Seoul. But that was when North Korea's army was much stronger.
Improving our sealift would be better. And perhaps putting Army equipment ashore or on ships (and keep them safe or defended, of course) near potential theaters (as we already do) so the troops can be airlifted in would be better, I think.
From the demand side, the Army hopes that it can operate without the need for all the supplies that we have traditionally used but which might be hard to get:
In the future operational environment, up against near-peer adversaries, the U.S. Army will be expected to be able to operate in smaller, more dispersed units far away from well-established military posts that offer creature comforts as well as essentials like fuel, water, ammunition and energy.
So the service is crafting a strategy to reduce the logistics tails for units expected to operate at the tactical edge.
Good luck with that.
Given the Russian and transportation situations, I'd return a corps with the bulk of two divisions and supporting arms to Europe.
You can't fight if you can't get to the battlefield and count on resupply.