We are speaking very much out of topic. The fact that I’m personally against NATO adds nothing in the debate on whether a nation state was behind these attacks. But lets entertain this anyway[1].
Crimea was annexed by a militaristic nation from a smaller less—but still quite—militaristic nation. Ukraine is neighbored to the west with supporting European nation—some with a really big military, and even nuclear weapons. None of those were able—or even willing—to stop the annexation. In this instance these armies were useless.
China annexed Tibet in the 50s and it wasn’t stopped. What makes you think Taiwan would be any different? China is a dictatorial power that is committing a genocide against a religious minority in the Xinjiang Uyghur Autonomous Region. It is not stopped. What makes you think Hong Kong would be any different?
Please note that invasions, and wars are not the only ways to act against human rights violations. There is also sanctions and boycotts. This was particularly effective to stop the South African apartheid. But alas, the current world powers are unwilling to apply even that to try to stop China from their human rights violations.
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1. Even though I’ve had this conversation dozens of times, and the idea of military is so engraved into people that the idea that we don’t need it—or worse is harmful—is too alien for people to even contemplate.