Considering that royal houses are all linked or related, why did no one step in and intervene? The Kaiser was the emperors cousin, and the empress was the granddaughter of queen victoria. My understanding is that they were held captive for a while before being executed. I can't imagine any figure, whether it's a head of state or an autocrat, going through the same thing without international intervention.
Were there other factors in play that prevented other countries from taking a stand or did they just turn a blind eye?
I don't really understand what you mean by not intervening, Britain, the US, France, Italy, Japan and a host of other powers intervened in the Russian civil war following the fall of the Romanovs. Granted, most of the stated aims of the intervention was about preventing the collapse of the Eastern Front and protecting Allied materials and interests, but you can't say the other countries sat on their hands throughout the whole affair. Japan alone had 70,000 troops involved in the intervention (both to guard the north and to combat communism).
Were there other factors in play that prevented other countries from taking a stand?
Like being embroiled in WWI, for instance?