Only when backed by force. There is no higher power in the playground of states. Ultimately countries by themselves are not necessarily rational actors. Smaller states join larger power blocs (either coerced or voluntarily, essentially they are trading off sovereignty for protection) and their own individual freedom to act gets subsumed. When it comes to dealing with Great Powers, realism is about as good as we can get, it is also predictably one of the oldest schools of thought in political science. The LIO theory is great in the decade post Cold War, but the world is multipolar now.