No need to make excuses for Russia. You can condemn the aggression while still understanding why it was a rational move based on the actions of others. The Russian government drew a very clear red line that Ukraine was to not be admitted to NATO. Russia's existing fears were likely stoked by the Banderite government in Kiev given its Russophobia, Islamophobia (remember Russia is like 10% Muslim) and glorification of Nazi collaborators like Stepan Bandera. There's a very real concern if an aggressive nation right on your borders, that promotes ethnic hatred, joins NATO, you're fucked if those Nazis get any ideas.

The US and other western leaders as well as NATO leadership pretty much stonewalled every attempt at diplomacy Russia made in the weeks before the war to address these concerns. This would not have happened if NATO would have agreed to Ukrainian neutrality. Russia is to blame for their aggression, but looking at the situation in full, their motivations are pretty clear and at least understandable. It's certainly more understandable than the US's motivation for invading Afghanistan - the Taliban was willing to prosecute al-Qaeda/bin Laden without a fight -let alone Iraq, and no one sanctioned the Bush regime or tried to isolate America from the world economy.