Under old-school journalism, reporters would be camping in front of Joe Biden’s campaign offices asking questions on his foreign policy: whether he still thinks Qatari-funded jihadis wanted to topple Syria’s Bashar Assad, if Libya intervention under President Obama was a mistake, and the reason for the flop of Obama’s Asia Pivot. In the last few weeks, Joe Biden has shown he would say anything to be president, including first promising to cure cancer, then flip-flopping on abortion, and finally flipping on China.

American domestic politics are for Americans to decide when the election comes, but at a time Beijing is returning to Tiananmen form, no bigger issue needs further scrutiny than Biden’s China stance.

Biden recently said in Iowa that China is a “serious challenge” and threat, adding, “We are in a competition with China. We need to get tough with China. They are a serious challenge to us and in some areas a real threat.”

Funny, because in May, he mocked the China threat, saying, “China is going to eat our lunch? Come on, man…They can’t even figure out how to deal with the fact that they have this great division between the China Sea and the mountains in the east, I mean in the west.”

Biden then added that he is worried about President Trump’s tariff wars against China, which is arguably “exacerbating the challenge,” and said “if we do what we need to do here at home…we can out-compete anyone.” According to reports, Biden then said: “You bet I’m worried about China…if we keep following Trump’s path.”

While pondering the alternative way, Biden said he would force China to go green: “Biden will rally a united front of nations to hold China accountable to high environmental standards in its Belt and Road Initiative infrastructure projects so that China can’t outsource pollution to other countries.” Yes, good luck with that. It might sound plausible in a school kid’s Earth Day project, but not in the policy plans of the prospective leader of the free world.

This, is, of course, pure madness. There is no bigger potential challenge for the West, and especially for the United States, than the rise of a near peer-rival great power like China. At this very moment, Chinese government lackeys in Hong Kong are cracking down on the largest protests of 2019, where more than a million Hong Kongers are marching to stop China’s de facto takeover of Hong Kong’s justice system, which would allow any dissident to be packed off to trial in mainland China.

But that is not the biggest issue. The problem is China is a challenge unprecedented to U.S. policymakers. Chinese peacetime gross domestic product is overtaking America’s, and China is set to soon, as a percentage of relative power, eclipse all previous great power challenges that the United States has ever faced, including Imperial Spain, Imperial Germany, Nazi Germany, Imperial Japan, and even the Soviet Union.

To put it simply, the conflict of interest between the rising China and an established hegemon in the United States is inevitable. In international relations, it is known as “the Thucydides Trap“.

Consider the world of international politics like a snooker table. Unlike the domestic politics of a nation state, the international system is anarchic in nature. That is because, in domestic politics there is an established government that can decide and, if needed, enforce. The lack of hierarchy in international politics makes it anarchical, in Kenneth Waltz’s terminology, because there is no global governance, and any attempt to form a global empire would invite backlash from rival powers, while any attempt at global governance would result in a global war.

Naturally, international politics is determined by nation-states, and more importantly great powers, which are the single most important actors of world politics. And great powers rise or fall due to a variety of factors: stupid policies, ideological and military overstretch, spending more than one can afford, foolish wars and global policing, failure or decline in technological competition, juvenile or effeminate elites, and the biggest variable of all: time.

In that light, the Thucydides Trap comes in.

Throughout history, there has been one completely consistent pattern: Growing and rising powers always challenge established powers. From Athens and Sparta, to Rome and Carthage, to Napoleon, to the two World Wars, and the Cold War, this pattern remained the same. China and the United States are just the new avatars of this great game, as the actors change, but the game remains the same.

In this context, conflict does not always mean war. It could be a cold war, trade war, proxy wars, anything, but conflict between a rising and established power is inevitable. As J.J. Mearsheimer states in his book, China will try and push away the United States from Asia, just as the United States once pushed away European great powers from the Western Hemisphere.

Meanwhile, Biden is flip-flopping on this biggest challenge confronting the United States, tweeting friendship bands about how much he misses Barack Obama, and claiming there was not a hint of scandal during his eight years as vice president. For all his problems, President Trump has been forthright about the China challenge, much more than any current Democrat, or even a majority of the Republican leaders. In the future, this might be considered his legacy.

While most focus on tariffs and economics, China—with its AI research, space research, naval build-up, data and IP theft, and unfair trade practices—is a much bigger challenge than to suffer a dollar increase in the price of a beer can. There are questions already on how one should contain China, or what in itself is an intelligent containment strategy.

Some are pointing out their doubts about whether the present U.S. leadership and population is even martial enough to withstand the long-coming generational conflict. But whatever the case, to lightly rephrase an old and used proverb, you cannot choose whether to be interested in a coming Cold War, as the Cold War is already interested in you.

Biden’s callousness about identifying that and then his face-saving flip-flop is, therefore, the most troubling aspect of his candidacy. The less said about his Democratic colleagues, the better.