Antonyms for the phrase "carrying on war" could include words such as peacekeeping, diplomacy, and negotiation. These words all suggest a peaceful approach to conflict resolution rather than military action. Peacekeeping efforts involve maintaining peace and stability in areas affected by conflict, while diplomacy involves negotiations and compromise to find a solution that benefits all parties involved. Negotiation is all about finding common ground and reaching an agreement through compromise. These approaches prioritize peaceful solutions over war, and are usually more effective at achieving long-term peace and stability.