Two realities define the range of a meaningful debate on Iraq policy: The war cannot be ended by military means alone. But neither is it possible to "end" the war by ceding the battlefield, for the radical jihadist challenge knows no frontiers.
An abrupt withdrawal from Iraq will not end the war; it will only redirect it. Within Iraq, the sectarian conflict could assume genocidal proportions; terrorist base areas could re-emerge.
Under the impact of American abdication, Lebanon may slip into domination by Iran's ally, Hezbollah; a Syria-Israel war or an Israeli strike on Iranian nuclear facilities may become more likely as Israel attempts to break the radical encirclement; Turkey and Iran will probably squeeze Kurdish autonomy; and the Taliban in Afghanistan will gain new impetus.
That is what is meant by "precipitate" withdrawal - a withdrawal in which the United States loses the ability to shape events, either within Iraq, on the anti-jihadist battlefield or in the world at large.
The proper troop level in Iraq will not be discovered by political compromise at home. If reducing troop levels turns into the litmus test of American politics, each withdrawal will generate demands for additional ones until the political, military and psychological framework collapses.
An appropriate strategy for Iraq requires political direction. But the political dimension must be the ally of military strategy, not a resignation from it.
Symbolic withdrawals, urged by such wise elder statesmen as Senators John Warner, Republican of Virginia, and Richard Lugar, Republican of Indiana, might indeed assuage the immediate public concerns. They should be understood, however, as palliatives.
The argument that the mission of U.S. forces should be confined to defeating terrorism, protecting the frontiers, preventing the emergence of Taliban-like structures and staying out of the civil-war aspects is also tempting. In practice, it will be very difficult to distinguish among the various aspects of the conflict with any precision.
Some answer that the best political result is most likely to be achieved by total withdrawal. In the end, political leaders will be held responsible - often by their publics, surely by history - not only for what they hoped but for what they should have feared.
Nothing in Middle East history suggests that abdication confers influence. Those who urge this course of action need to put forward what they recommend if the dire consequences of an abrupt withdrawal foreseen by the majority of experts and diplomats occur.
The missing ingredient has not been a withdrawal schedule but a political and diplomatic design connected to a military strategy. The issue is not whether Arab or Muslim societies can ever become democratic; it is whether they can become so under American military guidance in a timeframe for which the U.S. political process will stand.
In homogeneous societies, a minority can aspire to become a majority as a result of elections. That outcome is improbable in societies where historic grievances follow existing ethnic or sectarian lines.
Iraq is multiethnic and multisectarian. The Sunni sect has dominated the majority Shia and subjugated the Kurdish minority for all of Iraq's history of less than a hundred years.
American exhortations for national reconciliation are based on constitutional principles drawn from the Western experience. But it is impossible to achieve this in a six-month period defined by the American troop surge in an artificially created state wracked by the legacy of a thousand years of ethnic and sectarian conflicts.
Experience should teach us that trying to manipulate a fragile political structure - particularly one resulting from American-sponsored elections - is likely to play into radical hands. Nor are the present frustrations with Baghdad's performance a sufficient excuse to impose a strategic disaster on ourselves.
However much Americans may disagree about the decision to intervene or about the policy afterward, the United States is now in Iraq in large part to serve the American commitment to global order and not as a favor to the Baghdad government.
It is possible that the present structure in Baghdad is incapable of national reconciliation because its elected constituents were elected on a sectarian basis. A wiser course would be to concentrate on the three principal regions and promote technocratic, efficient and humane administration in each. More efficient regional government leading to substantial decrease in the level of violence, to progress toward the rule of law and to functioning markets could then, over a period of time, give the Iraqi people an opportunity for national reconciliation - especially if no region was strong enough to impose its will on the others by force.
Failing that, the country may well drift into de facto partition under the label of autonomy, such as already exists in the Kurdish region. That very prospect might encourage the Baghdad political forces to move toward reconciliation.
The second and ultimately decisive route to overcoming the Iraqi crisis is through international diplomacy. Today the United States is bearing the major burden for regional security militarily, politically and economically.
Yet many other nations know that their internal security and, in some cases, their survival will be affected by the outcome in Iraq and are bound to be concerned that they may all face unpredictable risks if the situation gets out of control.
That passivity cannot last. The best way for other countries to give effect to their concerns is to participate in the construction of a civil society. The best way for us to foster it is to turn reconstruction step-by-step into a cooperative international effort under multilateral management.
It will not be possible to achieve these objectives in a single, dramatic move. The military outcome in Iraq will ultimately have to be reflected in some international recognition and some international enforcement of its provisions. The international conference of Iraq's neighbors, including the permanent members of the Security Council, has established a possible forum for this. A UN role in fostering such a political outcome could be helpful.
Such a strategy is the best road to reduce America's military presence in the long run.
None of these objectives can be realized, however, unless two conditions are met: The United States needs to maintain a presence in the region on which its supporters can count and which its adversaries have to take seriously. And above all, the country must recognize that bipartisanship has become a necessity, not a tactic.
Henry A. Kissinger heads the consulting firm Kissinger & Associates. This article was distributed by Tribune Media Services.