> short lead time

that russia may try to militarily annex eastern ukraine was rather obvious for many years. Ukraine sits between NATO and russia. A majority of its population had been in favor of joining the former. The eastern ukraine holds large reserves of natural resources and pro-russian separatists. The later are used as a casus belli for an ethno-nationalist anschluss. Lastly it is not like the 2014 war truly ever ended: there had been 410.000 cease fire violation in 2017 alone, for example.