Written:
Доздраздвует Советское Армея!
привет от героий
Supposed to be written:
Да здравствует Советская Армия!
Привет от героев
Translation:
Long live(or hooray to) Soviet Army!
Greetings from heroes


Judging by the text I would guess it is not from WWI but from a later period (probably WWII) because Soviet Army was called this way in 1946 and before that it was Red Army (1918-1946) and WWI happened even before that