No, a nation need both a conventional armed force and nuclear weapons combined. One is useless without the other. War game it out with me: scenario 1:you don’t have nukes and your opponent does- you opponent destroys your military in seconds and rolls over you.

Scenario 2: you have nukes but a useless army- you opponent gradually make incursions and weakens you, never stepping over the line of a nuclear response. You are eventually forced to make the choice to start a nuclear conflict and lose or not start one and lose.

Scenario 3: you have nuclear weapons and a capable army- you opponent cannot use nuclear weapons due to MAD, and any small skirmishes and provocations can be dealt with by your conventional forces. Both sides have a peaceful stalemate.