Some European diplomats and journalists believe that with Zelensky's approval rating tanking, the withdrawal from Afghanistan and COVID taking up all the headlines the government in Ukraine wanted more attention and aid from the US, EU and NATO in general.
Mostly because they're not yet in the EU or NATO they won't receive any COVID aid from the various EU programmes.
So in the second half of 2021 they pointed the US and NATO to the Russian build-up of forces among the border. Estimating and warning their allies that there was an 80% chance that Russia would invade.
The US doubted this but went to work anyway to counter this threat in various ways such as providing Ukraine with indeed more aid and military training and threatening Russia with consequences as well as putting NordStream 2 under pressure again.
Russia noticed this and in response increased their hostility towards the US and Ukraine in particular. Fearing Ukraine with US help would make a move on the Crimea (something he has been paranoid about ever since he took it).
Putin is also under quite a bit of pressure domestically and dealing with crises in Belarus and Kazachstan. In such situations he often resorts to a 'show of force'.
In conclusion Ukraine got the attention that it wanted from various countries (US, UK, France) but more than they bargained for because most leaders are under pressure and looking to increase their approval ratings.
All this has done is pour gasoline on the fire that is the collapse of the economy of Ukraine. And that is why Zelensky has been acting all 'why doesn't anyone think about the economy?' as of late and downplaying the threat of invasion.
Meanwhile by playing ball Putin got what he wanted without firing a single shot so far.
Completing the 'exercises' as a show of force, a parade of 'failed' diplomatic missions from the west, keeping Belarus in line, possibly a 'diplomatic' solution on the Crimea (because the EU doesn't want a conflict) and the US pulling out their military advisors and diplomats from areas that matter.
https://twitter.com/jimsciutto/status/1493364058480955395The Duma has now voted and asks Putin to recognize the Donbass as independent from Ukraine (and Russia).
https://www.dw.com/en/russian-duma-asks-putin-to-recognize-ukrainian-regions-as-independent/a-60783596