The Soviet side receives the initiative because a one-party state governed by a relatively small circle can decide that war serves its aims more readily than a broad alliance can. Brezhnev was not as personally dominant as Stalin, but power was still concentrated enough to make that decision plausible in the counterfactual. Once the same leaders manufacture and begin the war, their opponents have strong reasons to doubt any promised settlement, making negotiation difficult without a political change in Moscow. A later answer places May before a sharper decline in Brezhnev's health around August, with senior Politburo figures influential but not yet wholly in control.
Notable Point · 3:45:14-3:46:06
The leadership that starts a war may obstruct a negotiated peace
A small authoritarian leadership can choose war quickly, but its continued rule makes later assurances harder for the victim to trust.