In August 2004, with the Iraq War raging and his reelection months away, President Bush announced the most radical overhaul of overseas military basing since the end of the Cold War. The purpose of this so-called Global Posture Review: to enable the lean, mean fighting machine long envisioned by then-defense secretary Donald Rumsfeld—a flexible force that can fight up to four wars at once and respond quickly to crises, wherever they may arise.

The plan slashes conventional military bases in places like Western Europe—the so-called “little Americas” with their schools, streets, and malls—and shunts troops into bare-bones forward bases in far-flung locations, closer to the action and without the family amenities, places like Romania, Bulgaria, and Kyrgyzstan, frail democracies (or not), many with NATO aspirations and lax environmental laws. All this reshuffling isn’t cheap: An expert panel convened by Congress to assess the overseas basing realignment put the cost at $20 billion, counting indirect expenses overlooked by the Pentagon, which had initially budgeted one-fifth that amount.

In Africa, where the military is establishing a new command called AFRICOM, the Pentagon is busy planting lily pads, officially “Cooperative Security Locations.” US troops can use these low-key outposts to stash weapons and supplies, and to train local forces. In a crisis, boom! They can convert to a real wartime base.

Given the rapid changes in America’s global military stance, Mother Jones embarked on a project to determine what our men and women in uniform are up to, country by country. We mapped a strategy, recruited a research team, and then divided and conquered. The result: an interactive map that lets you zoom in to almost any place on the planet to learn something about US involvement there. To this we added commentary and reportage, and in the coming weeks we’ll be rolling out reflections from more than a dozen military scholars and thinkers related to the topics covered. These will appear at motherjones.com and be archived on the project home page.

Among the things an armchair analyst may glean from this package is that, despite its price tag, the Pentagon’s shift has paid a few strategic dividends. It has helped US troops quietly penetrate new territory at a time when America’s vast base network has run into fierce public opposition around the globe, a situation Chalmers Johnson examines in “America’s Unwelcome Advances.” And, as Herbert Docena demonstrates in “US Troops Retake the Dragon’s Lair”, the new tactics have allowed the Pentagon to rebuild a major strategic hub in the Philippines, whose senators sent US troops packing in 1991.

Lest leapfrogging around the map leave readers feeling untethered, here are a few points to put things into perspective. First, the Pentagon’s numbers, which we use here for consistency’s sake, often feel arbitrary. They cite US installations in just 39 foreign countries and territories, and show suspiciously low troop counts for countries we know are abuzz with American military activity, like Jordan, Pakistan, and the Philippines.

In fact, our research shows there are relatively few places on the planet where the US military isn’t active in some way. American soldiers regularly rotate in and out of key locations on humanitarian and training missions. From weapons to cash to attendance at US military conferences, from researching tropical diseases to extending host-nation runways to building ports, the Pentagon is there to help—in exchange for a little help from our friends: overflight and basing rights, port privileges, and legal immunity for the troops. (See “How to Stay in Iraq for 1,000 Years.”)

Where the US military doesn’t tread, it funds. Indeed, humanitarian and military aid from the United States have proved most useful in coaxing foreign countries to give us what we ask for. It’s no accident that 22 percent of US foreign aid, as Joshua Kurlantzick reports in our September/October issue, now flows directly through the Pentagon. Conversely, the US Agency for International Development funds military training in a number of countries.

And while America’s military dealings abroad are most often framed in the context of fighting terror, the true mission is often less about terror and more about gaining the obeisance of strategically located and resource-rich governments. While indeed some of our efforts are undertaken to quell truly bad guys and keep old foes in check—sometimes those efforts fail, as we saw in Georgia this month—many are geared to safeguard future energy supplies and to contain China, which the Pentagon identified as a potential future military rival as far back as 1998.

It was the 9/11 attacks, of course, that enabled the Pentagon’s push into new territory, and provided the blank check needed to reward cooperative foreign politicians with military assistance and help quashing their own internal rebellions. But with America’s post-9/11 political capital spent, it’s unclear where all of this will lead. Even as Russia reasserts itself and China grows, the US government borrows heavily to cover its off-the-charts defense spending—$587 billion this year. At the very least, as former National Security Adviser Zbigniew Brzezinski points out in this package, the next president (and just as important, our pork-crippled Congress) will need to reassess what America really needs for its security, and how much security we can continue to afford.

Michael Mechanic is a senior editor at Mother Jones.