It should have gotten more attention--but it seemingly did not.

On Sept. 11, while Russian President Vladimir Putin warmly greeted his Chinese counterpart Xi Jinping at the Eastern Economic Forum in Vladivostok, their armed forces held war games in Russia’s Far East Military district.

Though “Vostok 2018” (East 2018) may have been Moscow’s largest military exercise in decades, two issues really stand out: a unique level of Sino-Russian military cooperation and the possible strategic implications for United States in the Pacific region.  

First, the bilateral exercise. While some dispute the force numbers, Moscow asserts that approximately 300,000 Russian troops were joined by some 3,000 Chinese soldiers in a strategic level exercise on the mock battlefield.

Of course, troops from different (usually friendly countries) exercise together. And Russia and China have held many military exercises before, including a bilateral naval exercise in the far-off (for China) Baltic Sea in Northern Europe.

However, what is deeply worrisome is that Vostok 2018 could provide China -- which has not fought a war since its 1979 conflict with Vietnam -- with a treasure trove of military knowledge about modern warfare.

Fighting abroad since 2014, Russia has gained a lot of experience, including in hybrid warfare and insurgency operations in Ukraine and with expeditionary warfare, new weapons systems, an air campaign and counterterror-insurgency operations in Syria.

The Russians are also well known for their expertise and prowess in electronic warfare, which some consider a U.S. vulnerability.  

At the drills, the Chinese will certainly seek to learn the latest and greatest in Russian military science. Indeed, not wanting to miss any opportunity, China even sent an uninvited spy ship to Vostok 2018 to garner as much intelligence as possible.

(Beijing also sent a spy ship to observe the U.S.-led Rim of the Pacific (RIMPAC) naval exercise in 2014 when Chinese warships participated in parts of it.)

China will almost certainly use the information gleaned from Vostok 2018 to inform and improve the capabilities of the various services of the People’s Liberation Army (PLA), including some advanced weapon systems courtesy of the Russian arms industry.

Ultimately, the PLA could use the knowledge gained from the exercise in the Russian Far East against a range of potential Chinese adversaries, including the Russians (ironically), Japanese, Taiwanese -- and the Americans. 

Naturally, Russia and China should be rivals, considering their geography (e.g., long border) and a tumultuous history (e.g., the Sino-Soviet split), going back centuries. Nevertheless, they have also worked together to create a “multipolar” global world order to balance the preponderant power of the United States.

Indeed, it could be argued that strategic cooperation between Beijing and Moscow has reached a new level as both capitals face deteriorating relations with Washington over a range of issues.

Cooperation with Russia could further strengthen the increasingly muscular PLA, and this concerns America deeply. Beyond that is the effect that deeper Sino-Russian ties could have on a range of American interests in East Asia. 

For instance, in the South China Sea (SCS), Beijing claims 90 percent of these waters as “indisputable” Chinese sovereign territory, making it essentially a “Chinese Lake.” The SCS now has several Chinese militarized artificial islands. 

In fact, the United States recently (again) challenged China’s (legally unsupportable) maritime claims in the SCS with the transit of a U.S. warship near one of the disputed islands inside what Beijing calls the “Nine-Dash Line.”

These Chinese maritime assertions are troubling due to the possibility that Beijing may decide to try to deny air and or maritime access to, or through, the SCS at some point, hindering trillions in global commerce—much of it American. 

Interestingly, Russia has been diplomatically cautious in opining on the legitimacy of China’s Nine-Dash Line claim for a number of reasons. Moscow may opt to stay silent and allow others (e.g., Washington) to bear the burden of refuting Beijing’s assertions while reaping the benefits.   

Russia also supports China’s sovereignty claims on Taiwan. China considers Taiwan to be an “inalienable” part of People’s Republic of China (PRC), an assertion that Washington has long differed with Beijing over.

Moscow might stay out of the conflict over Taipei’s political future. Yet it might do little or nothing to dissuade Beijing’s aggression against the island. In fact, Russia may support the PRC’s moves in fora such as the United Nations, complicating any international response.

Then there is the matter of North Korea. Both Russia and China share a border with North Korea and have had a political, economic and military relationship with the country since its founding in 1948. 

While Russian and Chinese interests are not exactly aligned on the Korean Peninsula, it could be suggested that Beijing and Moscow do have a common goal in not seeing American power and influence grow in Northeast Asia. 

Though Russia would most likely prefer not to become involved in a Korean contingency between the United States, China, and the two Koreas, Moscow could well provide some level of support to a Chinese intervention. At the very least, Russia may well stay out of China’s way.

All of these scenarios would be extraordinarily significant for U.S. interests.

In the end, Russia and China are both pragmatic and opportunistic in their foreign policies. They aim to protect and advance their individual interests, and some of those overlap.

A Western-style alliance between the two is highly unlikely.

Nevertheless, the recent Vostok 2018 military exercise is reason for some alarm in that it signals a possible willingness by Beijing and Moscow to engage in greater political and military cooperation in the future if necessary.  

Without question, this could be inimical to U.S. goals and objectives. 

The Sino-Russian relationship continues to merit close scrutiny. In the post-Cold War age, it has sometimes been given short shrift, easily falling into the category of “Yeah, but…”

That is understandable considering the relationship’s history and the difficulty of analyzing ties between capitals from different parts of the world. But the development of this relationship will not easily be dismissed if there is a crisis in the Pacific involving Russia and China that deeply affects U.S. interests.