To avoid the United States and China falling into the Thucydides trap, both nations will be served if they embrace a strategy of Mutually Assured Restraint (MAR). Political scientists argue that history shows, since the days of the ancient Greeks, that when a new power arises and the old superpower does not yield ground quick enough -- wars ensue. However, the record shows that there are no historical Iron Laws. Indeed, Harvard's Allison Graham points to four cases out of 15 since the 16th century that were not war followed -- include the rise of the U.S. in the 1890s as a global power.
To stop the current mounting mistrust and military buildups between the U.S. and China, given that both states face urgent domestic needs, some content must be injected into the vacuous phrase both powers now embrace: that China ought to have a "new kind of relationship " with the U.S. MAR could do the trick. Accordingly, both sides limit their military build up and coercive diplomacy as long as the other side limits itself in the same way -- and the self restraints are mutually vetted.
MAR is a strategy that allows China to take the steps it holds are necessary for its self-defense without extending them to the point that they seem to threaten other states and the global commons. It further enables the United States to take those steps it considers necessary for its self-defense, for living up to its obligations in the region, and for the protection of the international order. These steps would extend the concepts that underlie the U.S.' SALT treaty with Russia to military buildup in general and to diplomatic maneuvers. That is, they would be based on what President Reagan called "trust but verify."
One step that readily illustrates MAR is the act of capping the number of anti-access/area denial (A2/AD) weapons, especially anti-ship missiles, that China holds in its arsenal. China holds that it needs these A2/AD weapons for self-defense; the U.S. views them as threats to the freedom of navigation in the high seas and to its ability to discharge its obligations to Taiwan, Japan, and other states in the region. Both powers should agree to limit the number and range of these missiles, that these limitations should be verified by agreed-upon methods, and that such short-range, defensive missiles might be provided to other states in the area, for instance Japan.
Applying MAR to ICBMs may be impossible at this stage, as China holds that it is so far behind the U.S. in this category of weapons that it refuses even to explore a SALT-like agreement. However, in the long run, MAR may include what some call "strategic stability," a cap on the ICBMs and similar strategic weapons by both states.
To extend MAR to cyberspace, both powers might need to agree, implicitly, that the use of cyber tools for collecting information about the other powers is so deeply entrenched in international relations that it may well be impossible to end the practice. However, both powers could agree to restrain from using cyber arms for kinetic attacks. Such agreed-upon restraint would of course be subject to vetting.
Under MAR, countries and territories on China's borders would be treated not as contested areas that both powers attempt to include in their military alliances, but as neutral buffer zones--similar to Austria during the Cold War. This applies especially to the Philippines and Vietnam, as the U.S. has increased its military commitments to both of these states without sufficient regard to the fact that such involvements may drag the U.S. into a war with China over issues that are not part of the U.S.' core national interests.
MAR would particularly effective if applied to U.S. and China positions regarding the future of North Korea . Here, MAR would entail agreement from both sides that if North Korea's regime were to collapse neither American nor Chinese troops would move into the country. Both sides and the world would be much better off if American troops were not based next to the Yalu River -- and if Chinese forces were not massed next to the DMZ. Given today's technological means, the neutrality of such a buffer zone -- that is, the absence of military forces of both sides -- is relatively easy to verify.
MAR need not be the only foundation upon which the future Sino-American relationship is built. There are several important areas in which both powers have complementary interests and in which they can work together, including nuclear nonproliferation, climate change, counterterrorism, and financial and economic stability. However, MAR could go a long way to prevent China and the U.S. from sliding toward the Thucydides trap.