At its height, the Roman Empire had 47 major military bases scattered throughout the lands under its control. When the British were running their empire, they had 36 bases.

What happened to these empires? The cost of maintaining them bankrupted them. They were unsustainable.

We don't like to call ourselves an empire, but look at the numbers:

There are, according to the Department of Defense's "Base Structure Report" for FY 2009, 716 U.S. military bases on foreign soil in thirty-eight countries. Yet, according to the expert on this subject, Chalmers Johnson, the author of Blowback, The Sorrows of Empire, and Nemesis, that number is far too low: "The official figures omit espionage bases, those located in war zones, including Iraq and Afghanistan, and miscellaneous facilities in places considered too sensitive to discuss or which the Pentagon for its own reasons chooses to exclude -- e.g. in Israel, Kosovo, or Jordan." Johnson places the real number of foreign bases closer to 1,000.
from Same Empire, Different Emperor by Laurence M. Vance

Follow the link, the evidence gets even more damning.

It's no wonder we're broke. We still have 50,000 troops in Germany, I guess in case the Nazis come back.

"I will promise you this, that if we have not gotten our troops out by the time I am President, it is the first thing I will do. I will get our troops home. We will bring an end to this war. You can take that to the bank." - Barack Obama

We have one ruling party in America right now, it has 2 wings: The Democrat wing likes wealth transfer, taxes, and assaults on commercial liberties. The Republican wing likes deficits, war, and assaults on civil liberties. Both sides like power; and neither is interested in your freedom, or in toning down our empire. (ht Andrew Napolitano, who likes to point that out every chance he gets.)

All this in the name of national security? I think we'd find much more security if we brought the majority of those folks home.