The allied military intervention in Libya, which may still be in only an early chapter of a possibly long story, already has displayed multiple decision-making pathologies. Some of those pathologies resemble patterns observed in earlier wars, or the in the run-up to earlier wars. There is, for example, the phenomenon of a mighty power (the United States) getting half-dragged into a conflict by lesser allies (France and the United Kingdom), which brings to mind the European crisis of 1914, in which the actions of Serbia and Austria-Hungary dragged Russia and Germany into what became World War I. Then there are the ghosts of past genocides and non-interventions, which constituted the other half of U.S. decision-making. This has been more a matter of emotion than of clear-eyed consideration of costs and benefits. It is the sort of redemptive, analogy-laden “never again” attitude that also has been in evidence in other decisions about war and peace, similar to the repeated invocations of Munich and the pre-World War II diplomacy that have contributed to earlier wars.

Other pathologies are associated with the piecemeal nature of the Libyan intervention, which already has gone from no-fly zones to offensive strikes on government forces to allied advisers on the ground and now to U.S. missile-armed drones in the air. The incremental involvement, along with the rationalizations for the escalation, have been described as mission creep, and it is indeed that. Enlarging one's objectives in the course of a war is not ipso facto irrational. Vyacheslav Molotov referred to the “logic of war” in explaining why the Soviet Union expanded its territorial demands during the Russo-Finnish War; the military effort the Soviets needed to break through the Finnish lines was large enough to bring additional objectives into reach. But what has been happening with Libya is not the logic of another war; it's just plain mission creep, born out of confusion and disagreement from the beginning of the crisis as to what the mission ought to be.

A couple of other pathological patterns associated with incremental escalation of a war are likely to become more apparent as this conflict wears on. One is the tendency—irrational but common—to treat sunk costs as an investment. Another is the belief—incorrect but also common—that the more deeply the United States sinks into a conflict the more its credibility and standing will be damaged if it extracts itself from the conflict with anything other than a clear victory. That belief has figured into the prolongation of several wars, most recently the one in Afghanistan.

Another pattern associated with incremental involvement in a war is more logical than irrational, but the logic can still have a destructive overall effect. Each individual step on the ladder of escalation may be quite justifiable; it may entail a small incremental cost in return for increasing the chance that the whole expedition will end in a win rather than a loss. In Libya, each step may seem a small additional price to pay if there is reason to believe it might be just enough to make the difference between Qaddafi staying or leaving. But when all the steps are put together, they may add up to costs and consequences that outweigh even the value of a win.

In Libya, there may yet be a good number of steps to be taken. And the appropriate metaphor is probably not steps up a ladder but rather steps down into a bog. A departure by Qaddafi may be seen as a win, but that still would leave the question of what the allies should do about chaos in his wake (an op ed by Michael Chertoff and Michael Hayden raises important questions about this). An imperative to extend the intervention beyond Qaddafi would be driven by the dangers of chaos and power vacuums (including exploitation by radical Islamists) and by a sense of responsibility based on the Pottery Barn rule. And what about humanitarian considerations of the sort that supposedly were so important in getting us involved in Libya in the first place? If there was a moral imperative to save Libyans from violence not of our own making, what about our moral obligations when Libyans are endangered by violence that results from a situation that is partly of our own making?

The outstanding recent example of the failure of decision-makers to look ahead at the burdens that would follow the forceful overthrow of a dictator is, of course, the Iraq War. The intervention in Libya will not cause damage to U.S. interests as severe as that enormous blunder, but it threatens to become one of the more distracting enterprises of Barack Obama's presidency, despite Mr. Obama's clear reluctance to step into the bog.