You do not have leverage merely because you believe your position is reasonable.

Reasonableness is not leverage. Your position may be entirely fair and the other side may still have no incentive to accept it, because what moves an outcome is options, timing, and consequences rather than merit. Confusing the two leads people to hold firm on principle while their actual position erodes. Fairness is a good standard and a poor strategy.

Separate what is right from what you can achieve, and pursue both knowingly. Ask what would actually give the other side a reason to move. If there is nothing, being right will not be enough.