I think that they
can in the sense that they have the military capability to send forces into Ukraine, engage and probably defeat any Russian forces they encounter there.
The issue would be the
cost (in lives, in military capabilities expended, and potentially in the risk of nuclear escalation).
and will not protect Ukraine.
I'm not sure what they will do. Any military response will fall primarily on the United States, since western Europe has more or less outsourced its defense to the US at US expense. The US and the Europeans are blustering madly and the drums of war are beating loudly in the western media, but when it gets down to it, I don't think that NATO will send forces into Ukraine even if Russia invades (which isn't a sure thing by any means).
War isn't something to be taken lightly. Especially with a near-peer adversary with nuclear weapons. Given the potential cost of war, does protection of Ukraine represent such a vital interest that would justify assuming the cost? NATO's stated purpose is collective self-defense of its members. Ukraine isn't a NATO member, whether officially or unofficially (NATO in all but name. It's Russia's goal to ensure that never happens.) Ukraine's future relationship with NATO isn't such a vital interest to NATO as to justify war.
I suppose that Chinese media is talking war in your part of the world. If the US, Europe and Russia all got into a war, guess who the results of the war would benefit in relative terms? (Assuming the war didn't devolve into a full-scale nuclear exchange.) If the war was large, all of China's global rivals would be beaten down (like the Europeans after World War II), allowing China to assume its manifest destiny. Or if the war was more limited and less destructive, but was accompanied by the "crushing sanctions" that Biden loves to talk about, Russia would be pushed away from the West and into the arms of China, which would be of benefit to China too. Russia would stop banking in London and move its business to Hong Kong, furthering Chinese ambitions to become a global financial power. And if Russia attacks and the US and Europe don't enter the war, then China will probably try to portray them to the world as weak and untrustworthy allies (unlike strong China). China would almost certainly use it against Taiwan, saying 'If they won't protect Ukraine, what makes you think they will protect you??'
China probably thinks that if war breaks out, they win however things turn out. So sure, China will be beating the drums of war all around the world.