You're joking right? Ukraine has been preparing for war with Russia for 8 years now. Not only have they been preparing for 8 years now, they even signed a sham peace agreement with Russia back in 2015, trying to dupe them into thinking they wanted peace when in reality they wanted this war all along. Germany, Ukraine, the US and France have all confirmed this and even bragged about it. Signing a peace agreement with a nuclear armed neighbor, then trying to dupe them is a REALLY REALLY stupid idea.
Ukraine wanted this war all along, and guess what they got one and are getting slaughtered.
Here is a lecture by John Mearsheimer on the conflict back in 2015 which explains the entire history. BTW, the video has 30 million views. Enjoy:
BTW regarding the dam, it was reported back in Dec that Ukraine had already struck the dam with Himars to see if it could slow down Russian supply lines. Not only that, but the dam issue hurts Russia more than Ukraine. And lets not pretend like Ukraine doesn't like about stuff. Remember when they launched S300 missile that landed in Poland and blamed Russia? They still haven't apologized about it.