In bringing together Japanese Prime Minister Kishida Fumio and South Korean President Yoon Suk-yeol to forge a landmark security pact, United States President Joe Biden has advanced an ambitious plan to overcome his two allies' troubled past and usher in a new era of deterrence against common foes. But the initiative comes as China, Russia and North Korea have intensified efforts to shore up their own ties and mount a united challenge toward what they view as an attempt to replicate a U.S.-led, NATO-style military posture in Asia, revitalizing Cold War-era frontlines at a particularly volatile moment for the region….