This analysis examines how the diplomatic theatre of the US–Israel–Iran war has become nearly as consequential as the military one. Pakistan has emerged as a relevant indirect channel between Washington and Tehran, Turkey is testing a broader regional crisis-management role, Saudi Arabia is seeking to avoid strategic marginalisation, and Egypt is reasserting its weight in a major regional file. At the same time, Iran is using military and energy pressure to expand its negotiating leverage, while the European Union remains outside the active core of mediation. The central conclusion is that diplomatic relevance in the post-conflict order is being built now, from within the crisis itself, not after it ends.