There are two general issues that concern me when I engage in a continuing controversy over an important issue. First, I must be open to the possibility that I have gotten it somewhat wrong – specifically, that there are stronger arguments for the other side than I have previously understood. Publicly changing my mind is never fun, but it is better than sticking with a weak argument.

The opposite danger is that I will impute arguments to my opponents that are weaker than the ones that they rely on. I achieved a reputation for being a good debater in my political career in substantial part because I listen closely to what my opponents say and analyze it, pointing out its inconsistencies with some of their prior statements, or its problematic implications.

No public policy argument is more important today than the defense of President Obama’s decisions to withdraw U.S. combat troops from Iraq and Afghanistan, after America has spent more than a decade and far more than a trillion dollars in these efforts. There is no socially responsible path to holding down the growth in our deficit that does not begin with ending the continued annual expenditure of tens of billions of dollars a year in those two countries.

The counterargument is that it is necessary for America to continue these commitments because more needs to be done before we can be confident that those forces in each country with whom we have been allied will be able to maintain control. And we are told that if they do not maintain control, greatly increased terrorism will be unleashed on America.

My responses have been twofold. First, I do not think it is within our power, as desirable as that might be, to use our military to reshape Iraqi and Afghan society to the point where the people we would like to see running the country have the military, political and social strength on their own to do so.

My disappointment at that is mitigated substantially by the fact that this does not seem to me at all relevant to our need to deter terrorism within the United States. Even if we were able to make both of those countries entirely free of terrorist activity, there are more than a dozen other countries in nearby regions to which the terrorists could repair. There simply is not any way for the American military to plug every possible terrorist rathole.

My concern that I was being unfair to the other side of this argument did not fully disappear until I read an editorial in The Wall Street Journal on July 19. The statement in question was so stark and straightforward that it removed any fear in my mind that the opposition in this argument has a stronger case than I have conceded, or that I have misstated its arguments.

Here is what that editorial told the president he should be doing: “It’s not too late to undo Mr. Obama’s mistake and commit America’s support and troops to Afghanistan as we have in Europe since 1947 and South Korea since 1953.”

Note the unqualified insistence that our actions in Korea and Western Europe should be the pattern that Americans follow in Afghanistan – and by implication in Iraq as well.

While America began to withdraw troops from Europe in 1945, by 1947 Harry Truman had committed us to maintaining a very large military presence in Europe, which for much of the succeeding decades totaled 300,000. It has been brought down since, but there continue to be tens of thousands of American military personnel in Western Europe.

In Korea, while it was obviously necessary to keep troops there until the cease-fire of 1953, we have maintained a very large presence since. Both of these ongoing commitments were originally justified. There was strong reason to keep troops in Europe, although by the time the Soviet Union collapsed in 1990 it was clearly time for us to bring the troops home. We continue to spend tens of billions of dollars in Western Europe long after there is any military justification for doing so. I do agree that we should maintain a troop presence in South Korea, given the fact that it is under the threat posed by a heavily armed lunatic, who may be getting nuclear weapons.

But the point is that citing Europe and Korea as models is a clear call for an indefinite presence of large numbers of American troops in both countries for decades, with no endpoint.

My basic answer to the critics of the Obama’s entirely sensible decision to end U.S. military presence in Afghanistan and Iraq, recognizing that we have done as much as we possibly can to make them militarily self-sufficient, is that I do not see any rational alternative.

I continue to be struck by the insistence of many conservatives – Sen. John McCain, Sen. Lindsey Graham, The Wall Street Journal editorial board, Dick Cheney – that we continue to spend hundreds of billions of dollars in those countries indefinitely while they simultaneously demand that we cut back on the deficit, without any tax increases. The result of such action would, of course, be a devastation of funds for environmental protection, fixing our roads, maintaining Social Security and Medicare, providing access to public higher education.

Implicitly, the president’s critics concede one of the major points in favor of withdrawal – that it is simply not possible for the American military to bring about a situation in which the Iraqi and Afghan forces we support can maintain themselves in the face of armed internal opposition. A key point here is that it is “internal” opposition. I have heard that we need to stay in Afghanistan and Iraq because they do not have sufficient air power to defeat their enemies, which of course glosses over the fact that their enemies have absolutely no air power.

The fundamental problems in both countries are deeply social, cultural and political. The weakness of the people we would rather see prevail is wholly a product of their societies, and that is nothing that America can transform by outside military intervention.

So I am confident that I have in no way overstated the irresponsibility – physically and fiscally – of Obama’s critics. We have had a significant troop presence in Europe since the end of WWII and in Korea since the end of the Korean War. There is no sign in anything the journal says, nor in statements by McCain, Graham and Cheney, that indicates they are willing to settle for anything less.

After more than 10 years in both countries, we have been unable to bring about a situation in which the side we favor can maintain itself in power without our significant combat assistance. I wish that weren’t true. But a failure to recognize hard facts usually has disastrous consequences..

The view that America somehow has to fulfill the role of preserver of order virtually everywhere in the world at great financial cost, and at the peril to our military personnel, fortunately no longer commands a great deal of support among the American public. Obama should forthrightly defend his prudent, sensible decision to refuse to make the decades-long commitment to Iraq and Afghanistan than America made in an entirely different world nearly 70 years.

Barney Frank is a retired congressman and the author of landmark legislation. He divides his time between Maine and Massachusetts.

Twitter: @BarneyFrank