> led by an obvious despot that rigs elections and murders high profile citizens outspoken against them ... as part of an ongoing revanchist campaign ...

Sorry for asking, but how is this part relevant to the question? If the invading country were led by someone nice, or if its invasion were not a part of an ongoing revanchist campaign, would the answer to the invasion be any different?

My response as a private person would be no response. In an imaginary scenario where I had any political power, my response would be similar to that of India, China, Mexico, Cuba, Egypt, or United Arab Emirates. It probably makes me a bad person.