100y ago today's "Defense Ministries" were called "War Ministries". It is an already old euphemism or newspeak

When they want to be clear, they say "defensive" versus "offensive" operations.

On the other hand, there is no sense on warning a potential enemy if they are or aren't going to be attacked. Still, vagueness is necessary but newspeak is not.  A smart man can say nothing with correct language.

 They could say "we will take all measures we deem appropriate", or "all options are on the table", or "we will not allow this and that..." But using newspeak helps to increase confusion and dumbness. The less meaning, the better. More feelings, less facts.

But there are other related linguistic traps too. 
"Proportionality" is not "kill as many as they killed", or "using proportionate means". It means to do the minimum needed to neutralize the threat. The minimum may be much larger than the previous offence.