As tension on the Korean peninsula steadily increases, President Donald Trump appeared to serve ultimatums to both North Korea and China, its neighbor and most frequent trade partner. And he did it using his preferred method of mass communication: Twitter.

Gage Skidmore - flickr.com

Such language is a repeat of what Trump told the Financial Times in April:

"China will either decide to help us with North Korea, or they won’t. And if they do that will be very good for China, and if they don’t it won’t be good for anyone."

North Korea has already conducted three missile tests since Trump's inauguration, including its first launch of a medium-range missile, and a coordinated launch of four short-range missiles. The country has also rumored to be on the verge of conducting a sixth nuclear test, possibly with a warhead small enough to be fitted on a missile.

In response, the United States deployed the aircraft carrier U.S.S. Carl Vinson and its support ships to the region. North Korea, in turn, declared it was preparing for war, and unleashed belligerent threats about the "catastrophic consequences" of Trump's actions.

None of this is a major shift in either American or North Korean strategy. Tim Schwartz, CNN's bureau chief in the North Korean capitol of Pyongyang, wrote that the Carl Vinson had been deployed to Korea several times in response to threats by Kim Jong Un's regime, and that "the current tasking of the aircraft carrier group will not have any success in persuading Pyongyang to halting or even slowing down its nuclear weapons program, everything points to it having the opposite effect."

Likewise, hyperbolic North Korean threats about raining death and destruction on its foes are legion.

It's not clear what Trump means by "solving the North Korea problem," nor how China can "help" do this. However, Trump's tweets directly implicate China, who he just hosted for meetings.

Virtually all of North Korea's exported and imported goods go to and from China, which gives Beijing enormous leverage over Pyongyang. And the two nations have sparred of late, with China cutting off imports of North Korean coal after North Korean agents killed Kim Jong Un's brother, who had been living under Chinese protection.

China cutting off this trade would have a catastrophic impact on the nation. But even North Korea's nuclear tests haven't dimmed the robust economic relationship between the two nations, with China likely fearing the result of a North Korean collapse: millions of refugees pouring over their shared border, and the regime's nuclear weapons up for grabs.

With China unlikely to risk a North Korean collapse or nuclear response, it looks increasingly like the U.S., indeed, will have to act alone to deter the Kim regime's nuclear ambitions. And North Korea scholars worry this could lead to a U.S. first strike that could likely unleash a string of unpredictable scenarios.