Though Democrats and Republicans don’t always see eye to eye on foreign affairs, their goals and methods are in fact strikingly similar: seeking to advance democracy and human rights, fight terrorism and international crime, and prevent the kind of conflict we saw recently in Georgia, using U.S. military force when necessary.

Democrats typically hide behind the facade of multilateralism, preferring to use military force only when we have the blessing of the international community, such as the United Nations. Republicans usually are more ready to go it alone. Either way the United States still ends up meddling in the affairs of others in ways that would concern America’s Founding Fathers, who cautioned—as George Washington did in his Farewell Address—against military involvement overseas.

According to the Office of the Deputy Undersecretary of Defense for Installations and Environment, in fiscal 2006, our far-flung military empire included at least 766 bases in more than 40 countries. We had some 275 bases in Germany alone; close to 100 each in Japan and South Korea; 54 in Italy; 50 in Great Britain; 20 in Portugal; 19 in Turkey; eight in Bahrain. These do not include U.S. bases in Afghanistan, Iraq, Kyrgyzstan and Uzbekistan.

To support America’s network of international alliances, overseas bases and some 2.3 million men and women in arms, a manpower figure that both Barack Obama and John McCain apparently want to increase, the United States spends more than $400 billion per year, some 48 percent of total defense spending globally, not including the nearly $200 billion spent annually on the Iraq and Afghanistan wars.

The other countries of the world are not even in the same league. Even China and Russia, whose military budgets rank second and third globally, spend only a small fraction of what the United States does each year. In fact, according to the Center for Arms Control and Non-Proliferation, the U.S. spends more on defense than the next 16 highest-spending countries combined.

The logical question is: Why? Why do we have so much power committed overseas? Do we really need it and do we know when and how to use it?

Consider the Persian Gulf. Does the United States really need a large military presence in the Gulf to protect our access to oil?

As if we didn’t know it before the recent run-up in prices, oil is a highly valuable commodity and Persian Gulf countries are heavily dependent on it to earn foreign exchange because they have little else to export. In fact, the Persian Gulf countries need to pump and sell the oil at least as much as the United States and other Western countries need to buy it.

Thus, while there are no guarantees against temporary disruptions, the market in the long term will ensure that oil reaches the West. Even if instability in the Gulf makes the price go up, the industrialized economies will adjust, as they have over the last year. And if the higher prices help trigger an economic slowdown, prices will decline, as they have this summer. That’s how markets work.

It is a myth, therefore, that the United States must have military bases in the Persian Gulf to ensure the flow of oil.

The United States could eliminate most or all of its land bases in the Persian Gulf and elsewhere without compromising security or trade, relying on the Navy—offshore and out of sight; with its 11 large aircraft carriers and an equal number of smaller carriers—to do more of the heavy lifting. The United States could still be fully engaged in the world, with free exchanges of people, goods, money, ideas and culture and could still take military action when vital national interests, more narrowly construed, require it.

A meaningful debate on the proper U.S. role in the world is long overdue. The election campaign is a good time for this conversation to begin.

If reasoned debate does not lead to a more sustainable strategic vision, the United States is likely to be pulled into more Iraqs, at the expense of real security needs.

This article is adapted from a longer article, “Homeward Bound?” that appears in the current issue of National Interest, a quarterly journal of international affairs and diplomacy.