Question

stay in pact to entail regret or quit to ensure the nations disarmament explain

Answer 1

Here the pact means  that there is an agreement between both the parties on a certain matter.

Then the term regret means to feel upset.

The next term is entail which means to involve something into a particular matter.

And the last  word which is disarmament which generally means peace.

So the sentence stay in pact to entail regret means that there must be less wars in the nation so that a peace is maintained throughout.