In the Cuba context, the military thinking was that a blockade (an act of war) would lead to very quickly to a response and hence, open conflict, so why not initiate conflict with the strategic benefit of a surprise attack. The important part is that they acknowledged that a blockade was so severe, that a response was both likely and in a sense justified (though the latter is not important if you are rational).

Thankfully both leaders at least eventually recognized the cost of such a conflict and stopped following the insane logic of escalation to annihilation.

I make no equivalence between Putin's invasion and a "SWIFT blockade". I'm focusing on the foreseeable outcomes, not any sense of what is "justified".