During the invasion of Iraq in March 2003, 14 Australian Hornet pilots defied the orders of their American commanding officers. These pilots independently aborted 40 bombing missions at the last minute because they believed that the objects of attack were not valid military targets or that dropping their bombs would result in an alarming number of civilian casualties. Australian authorities reprimanded none of the pilots—they were following Australian rules of engagement. Had they been American they might well have been court-martialed.

Later that same month, just north of Basra, two American A-10 fighter pilots mistook a four vehicle British reconnaissance patrol for the enemy, even though the vehicles were decorated with bright orange panels to signal that they were coalition forces. Diving from 10,000 to 4,000 feet, the pilots bombarded the convoy with more than 500 rounds/second of armor piercing shells. The British tried in vain to raise the pilots on the radio, screaming for them to stop, but got no response—the Americans were on a different frequency. The planes turned and headed unwaveringly back towards the convoy, strafing their coalition partners a second time. The American pilots never saw—or understood—the red smoke released by the British, another coalition identification device. The "blue on blue" incident killed one British soldier and wounded another.

These two incidents are cautionary tales. They remind us that coalition warfare may both be far more costly in terms of human lives and material outlays than fighting alone.

On the surface, coalition warfare would seem to be far preferable to unilateral strategies. States share the burdens of fighting, increase the likelihood of prevailing by having more troops and resources available to prosecute the war, while simultaneously enhancing the legitimacy of the operation. Yet these benefits may not actually be real: coalition warfare may increase the burden of fighting to the United States and decrease the likelihood of winning, while not enhancing the legitimacy of the operation at all.

Ironically, at the very time the United States faces substantial criticism at home and abroad for being overly unilateralist, more resources than ever have been committed to coordinating operations, strategy, and weaponry with U.S. coalition partners and allies.

In the 2006 National Security Strategy, George Bush stated that confronting the "challenges of our time" through multinational efforts with other democracies is one of the paramount pillars of U.S. security policy. These were not empty words: the coalitions in Afghanistan and Iraq were, at their respective peaks, among the largest ever forged to fight alongside the American military.

"Coalitions" and "wartime alliances" are two types of what we call "multinational operations," which may also include other forms of multilateral cooperation, such as peacekeeping missions. By "coalition warfare" we mean wars fought by ad-hoc multinational forces that are forged to undertake a specific mission and then dissolved once that mission is complete. Coalitions operate in similar ways to "wartime alliances," although the latter may have a greater degree of institutionalization and may pre-exist a specific wartime operation. In some cases, coalition partners are largely symbolic—such as the Moldovans in Iraq who have 12 troops on the ground. Sometimes the contribution is more significant, like the NATO partners in Afghanistan where there is more parity with U.S. troop deployments (see the accompanying chart from NATO).

The Norm of Coalition Warfare

The size of U.S. coalitions has grown dramatically in the post-Cold War era. At the same time, the norm of fighting alongside others has become deeply entrenched. In the mid 1990s, these norms became increasingly institutionalized with the evolution of U.S. military doctrine to deal with the complexities of multinational operations. For example, in October of 1996, doctrine governing the U.S. Armed Forces in joint operations, and for U.S. military involvement in multinational and interagency operations, was established under the direction of the Chairman of the Joint Chiefs of Staff—a document that continues to be updated and revised.

Jointness became the au courant idea in the American military with the landmark Goldwater-Nichols Department of Defense Reorganization Act of 1986. At its core, the preoccupation with jointness was a commitment to coordinating the different branches of the U.S. Armed Forces. Yet, the jointness preoccupation spilled over into the arena of multinational operations as well, since at the same time that the military was changing, the number of multinational operations was on the rise. Hence, dealing with increasing jointness meant heightened operational coordination and integration with alliance and coalition partners.

The preoccupation with jointness in the U.S. military is not an altogether bad thing. Clearly, interoperability issues are critical, and above all, inter-service coordination is imperative to any military success. The problem is that it has left a legacy of our uncritical acceptance of the trend to larger and not necessarily more effective coalitions.

The Burdens of Friendship

Over the past two centuries, democracies have been more likely than non-democracies to fight via coalition, and indeed, the United States has never fought a major war single handedly. Yet, the transparency in democracies means that coalition dynamics become all the more intricate.

When countries such as the United States decide to fight alongside their friends, they must balance the twin objectives of maintaining support for the war at the domestic level, while keeping their partners in arms happy as well. Policy has to become distinctly Janus faced: domestic and international constituencies must both be appeased. In democratic states, where there is electoral accountability, this can be especially difficult. The dictates of alliance or coalition cohesion may come at the expense of the domestic will, or vice versa.

In maintaining close ties to the United States, for example, British Prime Minister Tony Blair undermined his own political career, and wreaked havoc on the Labour Party. Involvement in Iraq almost brought down the Spanish government, which the Spanish people replaced with a new one committed to withdrawing their forces from the Iraq coalition. In Poland, widespread domestic opposition to the war in Iraq has created a thorny political landscape for the leadership. In 2007, the war crimes case against seven Polish soldiers for killing Afghani civilians heightened already strident domestic criticism of Poland's troop deployments in Afghanistan and Iraq. In October of 2008, Poland withdrew its 900 remaining troops from Iraq.

The added complexity of coalition warfare derives also from the prerequisites of developing a coherent multinational fighting force. Harmonized military strategy is hard enough to design on paper, let alone to execute. States must use common or compatible doctrine, tactics, techniques, and procedures, which require a significant amount of coordination. In other words, there must be interoperability—not just in terms of weaponry, but also in terms of language, communications, doctrine, and the exchange of information. Planning for interoperability requires a considerable degree of familiarity with one another's commanders and staff, visits, the creation of liaison teams, multinational training exercises, and an assessment of the logistical interoperability among partners.

Coalition partners must communicate effectively at all levels to prevent the accidental killing of other allied units, which occurs all too frequently in coalition warfare. In the first Persian Gulf War, nearly a quarter of the American troop fatalities were a consequence of friendly fire. In addition, American troops killed nine British soldiers—as many as the enemy did.

Operation Enduring Freedom in Afghanistan has had several fatal incidents. The Americans have killed about 10% of the Canadians who have thus far perished in Operation Enduring Freedom, including an Olympic contender killed by American forces who accidentally strafed their own NATO allies in 2006. Friendly fire fatalities have become a significant source of friction between American troops and their Canadian and British counterparts.

In order to contain the number of such fatal incidents, the exchange of intelligence and information in coalition warfare is crucial. Yet, few militaries are quick to pass on such sensitive knowledge to representatives of other states. Even during NATO's 1999 Kosovo campaign, the United States withheld information about missions involving the use of advanced weapons systems to prevent leaks from allies. This created potentially dangerous situations when, for example, U.S. aircraft showed up on NATO radars without advance notice. During unilateral missions the chain of command and procedures is well established. Developing and coordinating and utilizing such structures effectively to facilitate the exchange of intelligence and information during multilateral operations is not always so easy.

Coalition warfare—and indeed multilateral operations in general—also requires harmonizing military equipment. If any of the U.S. coalition partners has out-of-date equipment ill-suited for joint operations, it often falls to the United States to provide it for them, or at least help provide it. For example, the United States paid approximately $240 million to Poland to be used for equipment, meals, transportation, and medical supplies when Poland first deployed troops to Iraq in 2003. In the 2005 Fiscal Year, the amount the United States paid the Czech Republic came to about $43,478 per soldier.

The costs of coalition warfare are not always balanced by the rewards. The 138 total Czech troops in Iraq and Afghanistan in 2005 hardly affected the security needs in either country. Further, because the United States is one of the few countries in the world with significant airlift capacity, the burden of flying in allies falls to the United States as well.

The complicated nature of multinational operations often reduces the speed and flexibility of forces in responding to any action on the ground. It also reduces autonomy in action. This can severely hinder wartime operations, as it did in NATO's war in Kosovo. The cumbersome decision-making structure in the conduct of that war made it a war by committee. The alliance was less efficient and effective as a consequence.

Costs of the Iraq Coalition

For all these drawbacks, the norm of fighting via coalition is so deeply embedded in the military practice of the United States that even the Bush Administration did not feel it could advance on Saddam Hussein without a broad-based coalition. Here, though, the coalition was not to augment power. Partners were bought to give the appearance of international support for the invasion, and the U.S. was prepared to pay dearly for this facade.

The United States offered numerous incentives to entice states to join the cause in Iraq—making cooperation generously worthwhile for partner states. The United States reportedly lobbied India with promises to sanction the sale of the Arrow 2 missile defense system by Israel, and to relax restrictions on the purchase of other state of the art military equipment. Pakistan was offered over $3 billion in military and economic aid. Turkey received $1 billion in aid and $8.5 billion in U.S. loan guarantees (it was originally offered $6 billion in aid and $24 billion in loan guarantees before the Turkish Parliament voted on March 1, 2003 to reject U.S. troop access to Turkish bases). U.S. contracts to help rebuild the Iraqi infrastructure were also among the enticements offered to its coalition partners.

Allies and partner states contributed troops at the United States' behest because the side payments make it worthwhile. For example, Moldova's troops to Iraq earned it a visit from Secretary of Defense Donald Rumsfeld, who thanked the country for its contribution to the war on terrorism and promised support in face of continued Russian military presence in the Transnistria region of Moldova. Poland has earned an anti-missile shield, and additional U.S. pledges of support in the event of an attack on it by a third party. In the Operation Iraqi Freedom (OIF) coalition in particular, small states that bring few military capabilities to the table have won disproportionate leverage over the most powerful country in the international system.

In short, coalitional fighting requires both political dexterity and logistical complexity. Fighting together may have benefits, but those certainly come at a price.

Winning the Wars

If coalition warfare has been costly to the United States in the contemporary era, then has it increased the likelihood of prevailing? The fundamental purpose of the U.S. Armed Forces, according to JP-1 (Joint Publication-1 of the Chairman of the Joint Chiefs of Staff), is "to win the Nation's wars."

The jury is still out in Afghanistan where there is more balance in the contributions of coalation partners—non-U.S. NATO troops in ISAF (the International Security Assistance Force) number about 29,810 to the United States' 17,790. In Iraq, however, where coalition forces number less than 7,000 to the United States' 146,000 it appears at this point that fighting via coalition has not enhanced the likelihood of victory. In fact, fighting via coalition may have actually undermined the ability of the U.S. to win.

From the United States' perspective, leading a war with dozens of coalition partners heightens the chance that one or more partners will abandon the alliance as the operation unfolds. This may happen despite the incentives offered by the U.S. to keep its partners happy. If coalition members do exit the war, it creates serious problems for the countries staying the course.

In Iraq, for example, as countries draw down troops or leave the coalition altogether, the United States has to keep its troops in Iraq longer than anticipated. This has a profound effect on combat motivation. Morale in the United States armed forces is at an all-time low, and the suicide rate, particularly among troops in Iraq, is at an all time high. In fact, the suicide rate of American soldiers in Iraq doubled from 2004 to 2005.

Concerns about the suicide rate in Iraq in late 2003 prompted the creation of a mental health advisory team, which reported its findings in December of that year and again in 2006. One of the findings of the report was that many soldiers felt hopeless and helpless. The single most important factor in contributing to those feelings was not knowing when they would be going home.

Every time an ally leaves the Operation Iraqi Freedom coalition, it underscores the war's unpopularity internationally and in the U.S. This is true, even if the number of troops in question is insignificant. If Moldova were to withdraw its 12 troops from Iraq, it would not likely affect the situation on the ground, but it would nevertheless represent one more country abandoning the coalition. Of the number of countries contributing troops to Iraq, 16 have already left the alliance while 23 remain.

Most countries that use coalition warfare are democracies, and it is precisely democracies that are especially vulnerable to the fear that others might abandon their coalition. Coalition cohesion is theoretically transparent in democratic states and the political leadership is electorally accountable. When states withdraw from a war effort, their actions affect public opinion in other countries adversely. As the public reads about states leaving the coalition, the sense of unfair burden sharing is heightened and the will to fight and win wanes (so too does support for the government in power). Spain's withdrawal from the OIF coalition had a backlash effect on public opinion in the United States and the United Kingdom. Troop reductions by the United Kingdom in Iraq have affected discussions of American troop levels as well.