The United Nations’ decision last week to authorize a no-fly zone and to bomb Libyan army positions in support of rebels battling the regime of Moammar Gadhafi marks the entanglement of the United States military forces in yet another Islamic country.

Emotionally, I fully understand the sentiment to want to bomb and punish ruthless dictators, and Gadhafi is certainly one, as was Saddam Hussein. But we’ve been told repeatedly that the United States is “broke,” that we’re going to have make sacrifices and tighten our belts. And whatever the level of understanding of our motives for military intervention in the Islamic world, many of our top military leaders, including Gen. David Petraeus, have acknowledged that bombing countries, especially killing civilians, exacerbates widespread mistrust and antipathy toward the United States in that part of the world.

On the home front, ordinary workers are coming under sustained attack because that’s what is supposedly necessary to remedy our budgetary ills. Tens of millions of Americans remain uninsured against major medical loss; states and local governments are cutting back on basic services while much of our infrastructure crumbles; and the economy remains mired in a tailspin the likes of which we’ve not experienced in decades. And in the midst of those depressing and grinding realities, we’re spending an estimated $160 billion annually just to prop up the regimes in Afghanistan and Iraq. Overall, the price tag for our war machine in fiscal year 2011 is more than $700 billion. (And a full accounting of all military-related spending puts the price tag at perhaps a trillion dollars. Per year.)

In light of these facts, why isn’t the military-industrial complex receiving more attention? Why aren’t we talking seriously about how overextended and arguably counterproductive is our global military presence?

One compelling answer comes from the military historian and political analyst Andrew Bacevich. Bacevich is a retired colonel who served in Vietnam and has become a trenchant critic of what he calls American militarism. His son was killed in action in Iraq in 2007. In his recent book, Washington Rules, Bacevich identifies an American Credo that “summons the United Statesand the United States aloneto lead, save, liberate and ultimately transform the world.”

And to fulfill that credo, the U.S. must maintain “military capabilities staggeringly in excess of those required for self-defense.” For example, many experts on global military expenditures estimate that the U.S. spends as much money on its own military as does the rest of the world combined.

The American Credo and attendant posture is, of course, not new. It has been accepted by every sitting American president from Truman to Obama. But given the dire straits on battlefields around the globe and on the home front, it has perhaps never been more urgent that we subject this credo to scrutiny.

In the wake of the Vietnam disaster, there appeared to be an opening in the political system for contesting our aggressive, forward military posture, though that didn’t last long. Anti-war politics did re-emerge among elements of the Democratic Party during the second Bush administration. As easy military victory against Saddam turned into a bloody counterinsurgency and civil war, anti-war voices became louder and played a role in Democrats’ major victories in the 2006 midterm elections. Barack Obama emerged as a surprise front-runner for the Democratic nomination in 2008 by touting his opposition to the Iraq fiasco and contrasting his judgment and prescience with that of Hilary Clinton, whose 2002 vote in favor of the Iraq resolution was now a serious liability.

But this was mainly politics and never meaningfully questioned the premises of American militarism itself. During the 2008 general election campaign, Obama made quite clear that he didn’t intend to challenge any of the deep-seated foundations of American militarism that have built up over decades, promising, for example, to extend America’s presence in Afghanistan. What opposition he continued to voice to some of the practices of the global war on terrorincluding the abuses associated with Guantánamo Baywas largely dispensed with once he became president.

Today’s Republican Party is certainly not going to question maximum militarization (though there are some dissenting voices within the party about unacceptably high military spending levels, like Kentucky’s Sen. Rand Paul). And the Democratic Party, despite a history of tolerating some notable anti-war elements, is certainly not going to stake its political fortunes on defying the longstanding elite consensus concerning America’s global military prerogatives.

As for public opinion, the picture is mixed and confused. Some polls find that Americans want to reduce military spending. Other polls don’t. But polls have consistently found that Americans have wildly inaccurate perceptions of what we actually spend our money on. Americans typically vastly overestimate how much of the federal budget is devoted to foreign aid, for example, while often underestimating how much of the budget goes toward the military.

A recent Rasmussen poll that found a majority of Americans opposed to reducing military spending also asked respondents the following question: “To ensure its safety, should the United States always spend at least three times as much on defense as any other nation?” Most respondents rejected this proposition. But in fact, the U.S. spends an estimated seven times more than China, the country with the second-largest military budget. In other words, respondents in this poll appeared to oppose reducing military spending based on very faulty premises about actual spending levels; these findings are typical.

It’s debatable the extent to which public opinion plays in American foreign policy decisions in general and war planning in particular. Americans long ago soured on our involvement in Afghanistan. But our political leaders continue to authorize more troops, more money and a deepening commitment there. Similarly, Americans’ initial support for the war in Iraq quickly devolved into clear opposition, with no meaningful impact on our presence there for years afterward. And a spate of recent polls shows a majority of Americans opposed to the kinds of military actions we’re now engaged in over Libya.

Of course, powerful vested interestsBoeing, General Electric and Xe (the company formerly known as Blackwater) to name a feware served by the perpetuation of a massive military-industrial complex. A pliant and often eager corporate media also makes it relatively easy for administrations to spin their war plans in the most favorable terms possible, while allowing them to avoid uncomfortable questions about our selection criteria for intervention, for example. Vested interests and the media reinforce the power of the credo to impose a creepy bipartisanship in military affairs.

And for all of those who wish that we had more bipartisanship than we currently do, it’s worth considering what that means in this case. Our war machine is responsible for significant blowback, imperiling our national security; a financial burden that is causing widespread misery and displacement at home; tens of thousands of American lives ended or broken beyond repair, with all the attendant consequences for the families involved; and the ongoing erosion of our civil liberties, all justified in the name of defending our freedom via global militarism.

That we appear to be rushing headlong into another conflictand yes, we can hope that this one will be a limited engagementsuggests that we remain unprepared to do the hard work of re-examining our global empire.

The portion of this column dealing with the American Credo originally appeared in Huffington Post.