Russia is pursuing low stakes, plausibly deniable, minor nuisance actions against the EU and U.S. It does enough to fool itself internally that it has a great enemy in The West, to which it is bravely standing up.

The purpose of this is to unite enough of the domestic population to suppress dissent and keep the current regime in power.

The reality is that it is actually at war with only one small neighbor, which is going so badly that they have had to import troops from North Korea. Embarrassing.

If they actually engaged in war with the EU, more specifically a member of NATO, they would lose quickly. So they stay well back from that line.