Those who feel, as I do, that the defense of the free world is not a business deal to which “art” can be applied, but rather a strategic necessity we cannot afford to shirk, are surely troubled by China’s military incursions into the East and South China Sea in the context of GOP nominee Donald Trump’s threat to “walk away” from a key ally in the region, Japan.

Trump recently commented on the unfairness of a treaty arrangement under which the U.S. is obligated to come to Japan’s aid if it is attacked but Japan cannot come to our aid due to a treaty which permits only a military dedicated to defense of the Japanese homeland. As the Telegraph reported on August 6:

Donald Trump has savaged Japan, one of America's closest allies, stating that if the US.is attacked, all Japan would do is "sit home and watch Sony television".

He expressed his frustration that the US is bound by treaty to defend the Asian nation but that if the United States is attacked, the Japanese cannot help because of Article 9, which constitutionally forbids it to send armed forces overseas.

He said that it "could be necessary" for the US to walk away from the treaty, or at least threaten to do so…

You know we have a treaty with Japan, where if Japan is attacked, we have to use the full force and might of the United States," he said.

"If we're attacked, Japan doesn't have to do anything. They can sit home and watch Sony television, OK?"

If Trump is suggesting Japan should repeal Article 9 of its Constitution and rearm, including going nuclear, he should say so. But walking away would be an invitation to Chinese expansion. While our trade deals with Japan may be unfair, consider the economic cost of a war between Japan and China over the Senkaku Islands in the East China Sea. The treaty he condemns is a powerful deterrent against this. And the foreign policy implications of a rearmed Japan in an Asia with long memories of Japanese militarism are problematic.

We defend Japan because it is in our national security interest to do so, not because it is economically fair, and we shouldn’t walk away because they sell us too many cars while rejecting our beef. And China’s recent actions show we are at a crossroads in history and had better make the right choice.

China is making military moves to defend its territorial claims in the East and South China Seas. In the South China Sea, it has been on a massive island-building campaign to provide moorings for its warships and airstrips for its air force, As Fox News noted on Aug. 9:

Satellite photos released on Monday appear to show China making progress on construction of at least two dozen hardened concrete hangars suitable for housing Chinese air force planes, including strategic bombers and inflight refuelers, on disputed islands in the South China Sea.

The photos were collected and studied by the Center for Strategic and International Studies (CSIS), a Washington-based think tank. They show construction work on man-made islands at Fiery Cross, Subi and Mischief reefs. The think tank reports the images were taken in June and July.

“These hangars are the smoking gun. You do not build nearly 80 hangars for civilian purposes on these tiny spits of land They're clearly meant for forward deployment of Chinese Air Force assets,” Greg Poling, Director of CSIS' Asia Maritime Transparency Initiative, told Fox News.

As these military moves are underway, Russia and China have announced that they will be conducting joint naval drills in the region in September. As the New York Times notes:

Russian naval forces plan to join Chinese forces for a joint exercise in the South China Sea, highlighting Moscow’s partnership with Beijing after a recent international legal ruling underlined rifts between China and Southeast Asian nations over rival claims across the sea.

The joint exercise will be held in September, a spokesman for the Chinese Ministry of National Defense, Senior Col. Yang Yujun, said in Beijing on Thursday. But he gave no details about the size of the drill or precisely where it would take place in the vast stretch of sea from southern China nearly to the Philippines.

“Following a joint understanding reached between China and Russia, the navies of the two countries will hold a joint military exercise in the relevant sea and air areas of the South China Sea in September under the name Joint-Sea 2016,” Colonel Yang said.

Such naval cooperation is not aimed at protecting freedom of navigation on the high seas. It is about protecting China’s territorial claims, claims similar to Vladimir Putin’s dream of reassembling the old Soviet Union, starting with annexation of Crimea and incursions into Ukraine. As Investor’s Business Daily has noted:

Beijing has long declared the South China Sea to be its territorial waters and has laid claim to two disputed chains: the Paracel Islands, about 200 miles from the coast of Vietnam, and the Spratly Islands in the southeastern part of the South China Sea. China's territorial ambitions include the Senkakus in the East China Sea, part of what Chinese military doctrine refers to as the "first island chain" that surrounds China.

In the South China Sea, as of February, according to Reuters, China had finished construction on no less than six different island reefs from which to project its power in the South China Sea. Included in its military effort is the construction of a 3,000 meters (9,842 feet) long runway on the artificially expanded Fiery Cross Reef as a base for Chinese fighter aircraft.

China’s claim to the Senkaku Islands in the East China involve islands which are under Japanese administration and which Tokyo claims as Japanese territory. Beijing has established what it calls Air Defense Identification  Zones in the East China Sea, one of which overlaps the Senkaku Islands. Beijing insists that aircraft flying through these zones file their flight plans in advance for the approval of Chinese authorities as part of its long-term plans to dominate the region. The Zones met only token resistance from the Obama administration: China also is laying claim to the Senkaku Islands in the East China which are under Japanese administration and which Tokyo claims as Japanese territory. 

Beijing has established what it calls Air Defense Identification Zones in the East China Sea, one of which overlaps the Senkaku Islands, a clear threat to Japan. Beijing insists that aircraft flying through these zones file their flight plans in advance for the approval of Chinese authorities as part of its long-term plans to dominate the region. The zones met only token resistance from the Obama administration:

China’s territorial claims threaten countries such as the Philippines and Malaysia as well as Japan. It also threatens war with the United States. China’s State Council, the Communist giant’s version of our cabinet, has issued a policy paper that declares Beijing is facing “a grave and complex array of security threats” that forces it to switch its strategy from defense to offense and that as a result China will increase its “open seas protection”.

This means that China is not about to give up its territorial claim in the South and East China Seas, which include the Spratly, Paracel, and Senkaku Island chains but will protect them with aggressive force if necessary. China will also continue its building of artificial islands as bases from which to strike. This is a clear response to President Obama’s “Pacific pivot” and an indication of how little Beijing is impressed.

An editorial in the Global Times, a newspaper seen as a mouthpiece for hard-line nationalists in Beijing, warns of the consequences of resistance: “If the United States’ bottom line is that China has to halt these activities, then a U.S. China war is inevitable in the South China Sea.”

In this context, Trump’s threat to “walk away” from Japan shows just how little tactics in the business world apply to the geopolitical world. Bad trade deals with Japan may cost us, but so too would a war with China in the East and South China Seas.

Daniel John Sobieski is a freelance writer whose pieces have appeared in Investor’s Business Daily, Human Events, Reason Magazine and the Chicago Sun-Times among other publications.