Over the past few weeks, the United States military has been participating in the NATO training operation, Trident Juncture. With 50,000 troops from 30 different nations involved, Trident Juncture is meant to demonstrate a high level of interoperability and cooperation among NATO allies and other friendly nations in the Arctic, where Russia’s military has enjoyed a near monopoly on strategic operations in recent years.

However, the massive American defense infrastructure allows for more than focusing on security one region at a time. While American troops in Norway participate in Trident Juncture with their NATO allies, the Nimitz-class aircraft carrier USS Ronald Reagan and its accompanying support vessels have joined another 57,000 participant strong show of force thousands of miles away, in the Pacific. There, the Ronald Reagan and its 6,000 sailors are joined by ships hailing from the U.S., Canadian, and Japanese Navies all intent on demonstrating their combined might and prowess to regional threats like China. The exercise, dubbed “Keen Sword,” is larger than previous iterations of the drill by some 11,000 troops — making it the largest war game of its sort ever staged in Japan’s coastal waters.

The drills will include an emphasis on anti-submarine warfare — a realm of renewed concern for America’s Navy. Both Russia and China have devoted considerable resources into their submarine warfare programs in recent years, while the United States has devoted the majority of its focus to counter-insurgency and anti-terrorism warfare.

The result is a far more competitive field amongst national submarine programs, with the United States retaining the advantage thanks to it’s massive infrastructure and global supply chain, moreso than its advanced submersible technology.  China’s navy, in particular, has been amidst significant expansion and modernization efforts, aimed specifically at gaining control over the entirety of the South China Sea in the short term, with global blue-water navy aspirations seemingly on the horizon soon thereafter.

Notably, tensions within the South China Sea relating to Chinese expansion resulted in an American and Chinese destroyer narrowly avoiding a collision last month, as both vessels attempted to demonstrate their unwillingness to give way in favor of the other. As American President Donald Trump and Chinese President Xi Jinping continue to engage with one another regarding limitations on trade between the two most powerful economies on the planet, these military friction points have come under increased scrutiny among defense officials that worry the combination of economic and diplomatic escalation could eventually manifest as direct military conflict.

“I think in 15 years — it’s not inevitable — but it is a very strong likelihood that we will be at war with China,” retired Lt. General Ben Hodges, who previously served as the commander of all U.S. Army forces in Europe, recently told the media. “The United States does not have the capacity to do everything it has to do in Europe and in the Pacific to deal with the Chinese threat.”