Furthermore, reciprocity matters. No longer is Washington dealing with a supine postwar Europe and Asia but rather an EU that has a larger economy than the United States and a Japan that boasts the world’s third-largest economy. Thus, if Americans must be prepared to come to the aid of allies, should not allies be prepared to come to the assistance of the United States if its people or forces are attacked? Absolutely. And that is why Washington should support Prime Minister Shinzo Abe of Japan, who has pushed through historic legislation in recent years to allow Japan to come to the aid of U.S. forces even where Japan itself has not been attacked.

Washington also needs to get the theory of the case right when it comes to the basic division of labor between the United States and its frontline allies. In light of the growing military challenge posed by potential opponents like Russia and China, armed as they increasingly are with formidable A2/AD architectures and rapidly deployable maneuver forces, the United States needs to encourage frontline allies in Europe and Asia to take a page from Moscow and Beijing’s playbooks. U.S. allies must develop their own A2/AD complexes in order to block or complicate easy seizures and to be more capable by themselves as first responders, especially in responding to “gray zone” situations. In particular, these states must do more to guard against unconventional and paramilitary threats, which are important components of the strategies of revisionist powers like Russia and China. This approach will necessitate allies focusing on the development of improved internal security, law enforcement, border police and coast-guard capabilities that stretch beyond the purely military domain. And it will require Washington prioritizing American unconventional-warfare capabilities, resident in the Army’s Special Forces, to advise and assist frontline states in dealing with ambiguous threats that fall short of clear military action. Frontline states must also do more to shore up their ability to provide areas relatively secure from missile or air attacks in which crucial U.S. forces flowing in can disembark and quickly maneuver. Fortunately, in encouraging these efforts the United States will, in many cases, be pushing on an open door, as the Baltic states, Poland, Japan and the Philippines are already taking initial steps in this direction.

As America’s allies become more capable of defending themselves by adopting modern technologies that deny the use of key warfighting domains—land, air, sea, space and cyberspace—to potential aggressors, the United States can better focus on two overarching military missions. First, the United States is the only country for the foreseeable future that can guard the so-called global commons—those vital arteries running across the oceans, through the air, undersea in the form of cables and gas pipelines, and through space that allow goods, services, information and people to flow safely. Those commons will be increasingly under threat from terrorists and revisionist powers alike, and their security cannot be taken for granted. Because U.S. allies have as much, if not more, of a stake in maintaining the freedom of the commons, they see tremendous value in the United States maintaining military forces to police them.

Second, the United States plays an indispensable role as a global swing force across the regions of the world. Wars can break out in any theater—or across multiple theaters at once. Yet the United States is the only country that possesses a full suite of global surveillance and strike forces in the form of stealthy, penetrating, long-range surveillance and strike aircraft, submarines and unmanned underwater vehicles, special-operations forces, cyber and electronic attack capabilities, as well as precision missiles and other munitions. These forces can deliver conventional, nuclear or nonkinetic strikes anywhere on the planet, and are a vital component of deterrence for the United States and its allies in the event of serious conflict with a highly capable opponent like Russia or China. The problem is that, while the United States is unique in its ability to provide global surveillance and strike forces, the proliferation of A2/AD capabilities necessitates new investments, including both land- and sea-based options, to ensure that the U.S. military will have qualitatively superior capabilities in sufficient numbers to make good on its global deterrence commitments in the years ahead. A new division of labor between allies and the United States should serve to free up resources for the United States to focus on maintaining its upper hand in this vital realm of global surveillance and strike capability.

Lastly, the United States must reaffirm the importance of extended nuclear deterrence and ensure its continued credibility. In particular, it must ensure that it has viable limitable and discriminate nuclear options to deter an adversary’s limited use of nuclear weapons so that the United States is never forced into a “suicide or surrender” situation over a distant ally. Washington should want to foreclose opportunities for hostile powers to ever see an opening where their limited use of nuclear weapons could reasonably be seen to yield advantages.

As part of this effort to maintain the credibility of its extended nuclear deterrent, the United States should also be willing to explore new methods of involving allies in its nuclear posture. This is already well established in NATO, where many of the allies participate in the nuclear mission by basing U.S. nuclear weapons, preparing for their delivery in wartime or committing to nonnuclear military operations to enable effective nuclear delivery. Such “nuclear-sharing” arrangements demonstrate that allies are willing to share the risks, costs and sometimes the opprobrium of shouldering the collective allied nuclear deterrent.

Taken together, the measures proposed here could help to revitalize existing alliances and put them on a firmer and more equitable footing. The era of complacency—both conceptual and financial—is over. Both the United States and its allies will have to do more to extract value from their common alliances and to redress the concerns raised by alliance skeptics lest these lead to strategic decoupling—and the advent of a far less stable world and a more menacing security environment.

 

THE UNITED STATES has assembled and maintained the most impressive alliance system the world has ever seen, a system that has been crucial in building and protecting a world order conducive to its security, friendly to its interests and congenial to its values. Constructing and maintaining this system has often involved sacrifices and not a few mistakes, and even compromise of interests Washington might otherwise have pressed. But it has served larger and longer-term interests. It has been an exercise in, to use Adam Smith’s old phrase, enlightened self-interest—a focus on the likely cumulative results of policies, rather than on their immediate debits and credits. For a uniquely powerful and great nation, this remains the best lens through which to evaluate America’s international policies, especially on issues where the penalties for error are so grim.

Lord Salisbury pointed out that the most common mistake in politics is sticking to the carcass of dead policies. It is certainly prudent to revisit long-standing ones. Inertia and sentimentality are no justifications for policies that risk American lives and wealth. But U.S. alliances do meet the searching scrutiny that should be applied to them. They surely involve costs, risks and inequities, but they also yield great benefits, and their realistic alternatives entail even greater hazards and uncertainties. Better to cultivate and adapt them than to cavalierly toss them away.

Elbridge Colby is the Robert M. Gates Senior Fellow at the Center for a New American Security. Jim Thomas is a principal with the Telemus Group and former deputy assistant secretary of defense for resources and plans.

Image: Polish army military police​ soldiers during exercise Steadfast Jazz 2013. Flickr/U.S. Army Europe