Japan is entering a dangerous political moment — one that risks unraveling decades of regional stability, undermining the legacy of the post-World War II settlement, and pulling East Asia into a new era of confrontation. What is unfolding is not an incremental policy shift but a strategic break with the cautious approach Japan has maintained since 1945. And as Tokyo repositions itself, Beijing is signaling, unmistakably, that it will not tolerate this transformation lightly.