In the US, the FBI recently arrested ten alleged Russian spies, who had been sent to the US in the 1990s, assuming American identities and attempting to befriend influential businessmen and weapons scientists. More details on the alleged spies (and more here); by all accounts, it seems that they weren't spectacularly successful at stealing secrets; one or two of them were better at milking their expense accounts, but others seemed to have lost the trust of their handlers; their tradecraft also seemed rather old-school, with the addition of a few new twists such as uploading data to surreptitious WiFi access points in cars. Meanwhile, David Wolstencroft, the creator of BBC spy series Spooks, describes the incident as Smiley's People with a laughtrack.
Some of the alleged spies took the cover of married couples; apparently they were paired up in Russia by their handlers and given their identities, before moving to America and actually having children together as part of their cover. The children are now in state custody, and their parents, should they end up in federal supermax prison or deported to Russia, are unlikely to see them again. I wonder whether hypothetical American sleeper agents abroad would go to quite that extent to maintain a cover or whether that degree of acceptance of individual sacrifice (both on the agents' part and that of the children brought into the world essentially as cover props) for a collective goal is specific to Russian culture.
Meanwhile, according to MI5, the number of Russian spies in London is up to cold war levels.