There might be several reasons for that.
First, Russia had deployed major forces into the region. One year ago, the situation was different.
Second, I think they could have some other reasons for this provocation: the upcoming presidential election in Ukraine, the G20 summit or some other things. I would not like to make any presumptions on that, but the situation is very clear. They had been escalating the situation in the region, and that was a natural continuation of the upgraded military presence in the region.