Militaries Less Successful at Difficult Tasks than Easy Ones

Shankar Vedantam looks at some recent quantitative studies by political scientists that demonstrates that countries with vastly superior military forces frequently fail to impose their political will.

He notes that while advocates and opponents of a given war will cherry pick historical analogies that suit their purposes, scientific studies will use large datasets to give a fair overall picture.

Political scientist Patricia Sullivan recently decided to take a different tack than the political pundits. Rather than look for a single war to provide insight, Sullivan decided to look at all post-World War II conflicts between the five permanent members of the United Nations Security Council and weaker nations. Her findings will probably surprise you — and would make for sober reading at the White House: Although the United States, the United Kingdom, France, Russia and China were militarily superior to their opponents in every one of the 122 conflicts that Sullivan studied, these powerful countries failed to win an astonishing 39 percent of their wars against weaker opponents.

Other research backs up Sullivan: New York University professor of politics Bruce Bueno De Mesquita has shown that, in conflicts between unequal powers over the past 200 years, the weaker country has outdone its stronger foe 41 percent of the time.

Success rates between 59 and 61 percent aren’t terrible, of course, but not what you’d expect given the mismatches involved. The reason is that “success” has a political definition, not a military one.

Sullivan found that powerful nations tend to win wars when all they seek is an opponent’s submission, but tend to lose when victory requires an opponent’s cooperation. “On one end of the spectrum are things you can achieve with brute force,” she said. “On the opposite end is getting an adversary to change a domestic or foreign policy — you want the adversary to change his behavior.”

Pushing Hussein’s army behind a line in the 1991 Gulf War and overthrowing the dictator in the current war were aims that did not require the acquiescence of Iraqis; they could be achieved by brute force alone. But creating “a democratic Iraq that upholds the rule of law, respects the rights of its people, provides them security and is an ally in the war on terror” — goals that Bush laid out in his State of the Union speech last week — all require the cooperation of Iraqis.

Sullivan found that the five Security Council permanent members won three-quarters of conflicts in which their aims did not require their opponents’ cooperation, but only half of the conflicts in which they did need cooperation.

For the United States, the disparity was even greater — winning 81 percent of conflicts when cooperation was not required, but only 44 percent of the military interventions, such as in Laos in 1964 and Lebanon in 1982, that Sullivan described as having “coercive” goals. “In other words,” Sullivan concluded, “the United States has withdrawn its troops without attaining its primary political objective in 56 percent of the military interventions it initiated with a coercive war aim.”

This does not shed any conclusive light on the public policy debate (nor is it new; similar studies have been published for years with similar findings). Still, it’s useful to remind ourselves that imposing one’s political will using military force is difficult even if one has a decisive military advantage and that the military is a more useful tool for achieving some aims than others.

If one’s goals involve changing the behavior of a society, they will not be easily achieved using military means. That doesn’t mean that it should never be tried, merely that a sober cost-benefit assessment should be made. If diplomatic and economic means have been tried without success or there simply isn’t time to try them given exigent circumstances, then the military option should be considered.

The question at that point, though, is how important is success as compared to the costs in blood, treasure, and prestige involved. If the benefit to be achieved is merely nice, the mission should be deemed “too hard” and not attempted; if vital national security interests are at stake, then military means must be tried even if failure is a distinct possibility.

It’s noteworthy, too, that the 44 percent success rate of the United States in “coercive” conflicts is misleading. Because of our substantial power in the economic and diplomatic arenas–not to mention the awesome power of a mere threat of military force–the lion’s share of would-be conflicts are resolved without the use of force. Those that get to the stage of military deployment are, therefore, the most difficult. It’s not surprising, therefore, that the success rate is so low in those instances.

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James Joyner
About James Joyner
James Joyner is Professor and Department Head of Security Studies at Marine Corps University's Command and Staff College. He's a former Army officer and Desert Storm veteran. Views expressed here are his own. Follow James on Twitter @DrJJoyner.


  1. I think the old anology of using a hammer to fix every problem is most apt here. Hammers do make lousy screwdrivers.

  2. There is some truth to the idea that hammers make lousy screw drivers. And trying to use a hammer as a screw driver is not likely to yield success. But hammers make great hammers. They are very good at smashing things. A case can be made that our biggest successes in getting “cooperation” rather than “submission” came after we used the hammer to thoroughly smash the other side. When you don’t smash the other side to the point that ‘anything would be better than this’, then you haven’t used the hammer to its fullest potential. That may be appropriate at times, but it can also lead you to trying to trying to screw together bolts with your hammer.

  3. LJD says:

    In other news, governments are bad at ALL tasks- difficult or easy.