It can happen. It’s really up to Russia. The separatist rebels surely want more, and they are more likely than not to take Debaltseve. But if they do, the Ukrainian military leaves the premises, and the Ukrainian government decides to maintain the “ceasefire,” there will be an opportunity for Russia to take a breather and tend to its own wounds while capping EU and US (and Japanese wink-wink) sanctions and the cost of subsidizing the rebel territory economy. In the meantime, it will always have the option of unleashing the rebels again if it finds the direction the Ukrainian government is taking with regard to the EU and NATO not to its liking. I have to wonder if the Poroshenko administration will be willing and able to cut losses—I am reminded of the Japanese mindset before and during WW II—but who knows?
Now what in the world does that have to do with Japan? Well, if the ceasefire holds, the Putin visit to Tokyo will happen. Not much substance to come of it ultimately, I’m sure, unless the ceasefire holds long-term, but it will put Prime Minister Abe’s marker on the table.