Of course i understand George's fears: he was afraid to loose his throne. But as BlessOTMA pointed out, he could have put them in another country of the Empire, and saving them would have brought him great respect, IMHO - Nicky was his political and war ally, not only his cousin. I thinks this is a matter that goes beyond political threats. I'm thinking to French Revolution - the King and the Queen were prisoners from the very first moment, and there was no way for other countries to save them. But when they were executed, Austrian Empire declared war to France - to vindicate Marie Antoniette's death, i suppose, not ONLY for political matters.
I know that UK was one of the last european country to officially recognize Soviet Union as a state - as BlessOTMA said, at least he learned his lesson. (for example Italy, a "Red" country during WWI and first years after, was i think the first one to oficially recognize Soviet Union. For "Red Country" i mean that Turin, the town from which the Italian IF came from, was most socialist).