This article aims to highlight, in a realist perspective, the importance of Sino-US relations and the diplomatic steps taken by the main global actors in the context of the military actions in Ukraine. In order to provide an authentic portrayal of the characteristics of the international security environment and, in particular, of the Asia-Pacific region, with a focus on the Taiwan issue, I have taken an overview of the situation in the region, with reference to recent history and the current context, while showing the implications of Sino-American relations over security and the role of the AUKUS and QUAD alliances in the politico-military sphere. The current crisis on the international arena, triggered by the individual or joint actions of certain state actors, has political, economic and military aspects with serious repercussions for the whole community and affects global security to a degree that brings the military component to the fore. This “atrophy” is being addressed by a number of events taking place at different points around the globe, namely the war in Ukraine, the Asia-Pacific region and the Taiwan Strait, where the interests of major state actors are involved and are finding it difficult to reach a consensus.