About the Far East
We will not speculate on what will happen in the future.
But judging from the current situation, it should be unlikely~
1 External situation, China’s diplomacy in Southeast Asia has encountered many difficulties, and the countries in the first island chain have begun Harassment keeps China in check. We can guess that it was secretly instructed by the United States. This can be seen from the double standards of the United States when it comes to the Nansha Islands and Diaoyu Islands.
If we want to confront the United States, a superpower, and its allies, what I mean by confrontation is military and political balance. China’s own strength alone is far from enough. We need a strong and A powerful ally, and Russia is the best choice. There are advantages in all aspects including military, political and geographical environment. Once the war starts, as long as the two countries are each other's horns and rely on each other, they will have a very broad strategic depth and drag their opponents into a protracted war.
2 Topography, if I remember correctly, the Nerchinsk Treaty signed 1.4 million pieces of land. In fact, most of this land is frozen ground, very cold, and has little use value. , but there should be a large part of the minerals. If both parties have an agreement to jointly develop it, then it will have no practical significance who owns the land. Border protection in such a vast and cold place has become a big problem, and military regions must be re-established, troops stationed and patrolled. The cost of defending territory is too high.
In addition, the territory has been demarcated and there is no sovereignty dispute. Considering all factors, if there is no war, these lands should not be returned~