Truth may be the first casualty of war, but the language of strategic discourse has also suffered multiple serious wounds over the past decade -- none more grievous than that which has been inflicted on the time-honored concept of "preemption," the notion of striking first so as to thwart an adversary's own impending attack. The most egregious misuse of the term arose in President George W. Bush's 2002 national security strategy, which sought to expand its meaning to encompass the use of force against any who might one day pose a threat. Thus was the attempt made to justify the 2003 invasion of Iraq as "preemptive." But the attack on Iraq was not preemptive. In the strategic lexicon, the kind of action taken against Iraq is called "preventive war," which is about attacking before a threat becomes imminent. Moral philosopher Michael Walzer has parsed these matters neatly, noting that preemption focuses closely on the need to take action in a current crisis; preventive war has to do with worries about the future consequences of inaction. Generally, ethicists are open to the need to be able to take preemptive action. But the very concept of waging preventive war gets their backs up. It looks a little too much like naked aggression. Due to this concern, Bush and his senior advisers sought to defuse principled opposition to the use of force, in the absence of imminent threat, by arbitrarily expanding the definition of preemption. Humpty Dumpty got away, for a while, with the bald-faced assertion that a word "means just what I choose it to mean." But for national leaders and diplomats, this looseness is a recipe for disaster -- as the ensuing costly debacle in Iraq suggests. Even more troubling than the facts that Americans are gone from Iraq, al Qaeda is back, and the killing has continued, is that President Obama has taken the same approach to preemption as his predecessor. He has ramped up the global drone war on terror with a many-fold increase in strikes on suspects. We are told that this is done with great care, and that the targets are being selected strictly on the basis of the imminence of the threats posed. But this is hardly believable, as scarcely a shred of evidence has been presented to the public in support of the notion that the victims of these attacks were on their way to hit American (or other) targets. Further, the frequent use of "signature strikes," hitting at sites simply on the basis of intelligence profiles suggesting they're populated by troublemakers, is highly problematic. Another Obama administration application of preemption is emerging in cyberspace. Last fall, then-Secretary of Defense Panetta, in a major policy speech, explicitly spoke to the possibility of mounting preemptive attacks. For the most part, his qualifying "ifs" (if a cyber attack is perceived as imminent, and if it is likely to do great damage) suggest a degree of caution. But there has also been language in the administration discourse about striking first on the basis of "emergence of a concrete threat" that begins to move this policy more in the direction of using preventive force than just taking preemptive action. This is a serious concern, given how very hard it will be to detect an imminent attack. In cyberspace there are no troops massing on the border, no telltale signs of long-range missiles being readied for launch, no aircraft scrambling. Cyberattack comes with a simple click. Identifying the attacker ahead of time will require amazing forensic skills -- not in evidence yet even in the case of exhaustive post-incident investigations. For all the current troubles with the slippage from preemption to prevention, it must be noted that the history of strategic thought about striking first to forestall an imminent attack has been very troubling in its own right. Nuclear preemption notions during the Cold War, for example, led to highly destabilizing ideas about the "launch on warning" of one's vulnerable missiles. The Soviet hierarchy's war plan for central Europe was just as high-risk, too, as it called for a preemptive series of nuclear strikes from the outset of any conflict, before NATO would be able to use its own atomic arsenal. Both sides eventually had the good sense to realize that nuclear preemption made no sense, and mutual deterrence eventually held sway -- as it still does today. Even the classic case of preemption in a conventional conflict, Israel's opening operations in the Six-Day War of 1967, leaves much to question. One Israeli officer quoted at the time in the Associated Press noted simply, "Time is against us. Nasser said he seeks to destroy us. Why shouldn't we believe him? This sort of reasoning is preventive in nature -- that is, it speaks to attacking before the odds of winning worsen. Cost factors also drove the action back then, as mobilization of Israel's citizen army ran about $20 million daily (big dollars in those days, for a small country). A lingering crisis was going to ruin the economy. Even so, the great Israeli statesman David Ben-Gurion was not convinced that war was necessary, and wrote in his diary on the eve of the conflict: "I'm very worried about the step we're about to take. The haste involved here is beyond my understanding. Indeed, it is hard to identify cases of preemption -- save for those "spoiling attacks" featured at the tactical level in many military campaigns -- that do lie within our understanding. Francis Bacon no doubt had it right -- in theory -- four centuries ago in his essay, "Of Empire," when he asserted, "there is no question but a just fear of an imminent danger, though there be no blow given, is a lawful cause of war." But in practice, preemption has never made much sense as a strategic national policy. Further, the expensive misadventure in Iraq has made for real problems with the pursuit of preventive policies. Yet prevention may be the only rational way ahead, in terms of pursuing the twin goals of stemming proliferation -- in Iran and elsewhere -- and keeping weapons of mass destruction out of the hands of terrorists. So it is time for senior leaders to fess up. The past decade has seen a lot of stumbling around, with wrongheaded preventive actions taken and a sustained, bipartisan effort at Newspeak that willfully mislabels prevention as preemption. Given the inherent problems with preemption, though, let's just be honest about the need to act forcefully and preventively against proliferators and terrorists -- even in the absence of imminent threats. How hard is it to admit this?