War is the greatest disaster that can befall mankind. When one wishes to prevent a disaster, it is important to be in the habit of maintaining policies that can do so.

According to power shift theory, the outbreak of war follows a pattern; namely, war occurs when a militarily weak nation expands its military prowess, until it realizes that it has exceeded the military power of its neighbors. In this situation, the newly-empowered nation attempts to overthrow the formerly powerful states around it — in other words, the weak states of today — in order to cement its newly acquired position, resulting in war—a war of opportunity.

Nuclear Weapons Safeguard Against Large-Scale War

Currently, the U.S. is in possession of several thousand nuclear weapons and several hundred intercontinental ballistic missiles. With over 10 aircraft carriers in active deployment as well, it is the most powerful nation on earth. However, China is in the midst of a modernization program that includes several hundred nuclear weapons, some tens of ICBMs, and the construction of aircraft carriers. Perhaps a reversal of the current American military balance is upon us.

There are both large-scale wars and small-scale wars. Were both the U.S. and China to enter into a large-scale war, there is the possibility that each would be exposed to the nuclear attacks of the other. As of today, there is nothing either country could gain from a war that would be worth risking victims of nuclear assaults. For that reason, the possibility of a large-scale war between the U.S. and China is small.

But how about a small-scale war? When both sides have nuclear weapons in active deployment, it’s possible to stave off the sort of large-scale war that would lead to nuclear warfare to begin with. So long as a large-scale war is avoided, a war can be drawn to a close within a smaller arena. The casualties of a small-scale war are few, so there’s a chance that the benefits may outweigh the costs. Usually when people hear “diplomacy,” they think of the relationships between nations, but in the real world, diplomacy, strong-arm diplomacy, includes military-dependent tactics like intimidation and mobilization—small-scale war.

According to power shift theory, war breaks out when the military power of a nation trying to alter the status quo exceeds the power of a nation trying to preserve the status quo. Currently, the U.S. is the champion, and maintaining the status quo is to its benefit. On the other hand, China, considering its activities in the East and South China Seas, is the nation seeking to change the status quo. In the event that the military of the belligerent state, China, surpasses that of the status quo state, the U.S., the possibility of war increases. However, even in the event of a war between the U.S. and China, it would be a small-scale, not a large-scale war.

China’s Rise Invites a Small-Scale War

A small-scale war is a war covering a limited area, with a limited amount of troops. A small-scale war between the U.S. and China would occur in a place where there is a possibility that China’s military might prevail over that of the U.S. The combined forces of the U.S. military currently overwhelm the combined might of China. However, missiles have ranges, and warships and warplanes have cruising ranges as well. As a general rule, air superiority diminishes over distances following an inverse-square law. For that reason, the further the war is from the U.S. — and the closer to China — the greater the odds are in China’s favor.

Once the U.S. and the Soviets became strike-ready anywhere on earth with ICBMs, it became common to say that distance was no longer a large factor in war. However, in the case of small-scale wars, no nuclear weapons — let alone ICBMs — can be used. The outcome is determined by the relative merits of the warships and warplanes that are able to appear on the battlefield.

So, in the event that the U.S. and China plunge into a small-scale war, likely somewhere close to China such as the East China Sea or the Western Pacific, which military would be better off?

In modern warfare, those who dominate the sky dominate the battlefield. Warplane combat radii range from a few hundred up to about 1200 miles, and the missiles that can be used in small-scale warfare have about the same range. Therefore, warplanes and missiles both need to be within that range. Put another way, the battlefield of the small-scale war must be constricted to that distance from military bases.

The American Advantage in East China Sea Bases

As stated above, the U.S. has 10 aircraft carriers in active deployment, which could be considered mobile bases. These carriers can deposit hundreds of warplanes into the fray, regardless of the location of the battlefield.

On the other hand, as China has no active carriers, they are restricted to locales within several hundred to 1200 miles of a land base. Without constructing a base in the South China Sea — like the Spratly Islands — China’s military power cannot reach across the whole of the sea. This is one of the reasons for China’s unilateral reclamation and construction of a base on the Spratly Islands, hotly contested with the Philippines. Nevertheless, China’s land bases outnumber America’s carriers, and the number of sky-ready warplanes surpasses the U.S. as well.

In a schematic that pits Chinese land bases against American carriers, the U.S. does not necessarily always reign supreme. However, in the event that the battlefield is the East China Sea, a few hundred to 1200 miles away sits Japan. Since the U.S. can use Japanese bases, the U.S. would hold both land bases and carriers, and could situate itself in a position more advantageous than that of China.

Accordingly, provided the security treaty remains in effect, even if there is a war in a location close to China and far from the U.S., like the East China Sea, the U.S. will be able to deploy forces for a small-scale war at an advantageous position. So long as the security treaty remains in effect, it will not be possible to enact a reversal in the balance of military power between the U.S. and China, and in accordance with power shift theory, a war will remain unlikely. Thus, the key point in preserving the peace in the East China Sea and the Western Pacific is the continued existence of the Japanese-U.S. alliance.