What primary purpose do countries safeguard nuclear weapons for?

Countries primarily safeguard nuclear weapons to deter aggression from other nations. The presence of nuclear weapons serves as a powerful deterrent, discouraging potential adversaries from initiating conflict or aggressive actions, particularly due to the catastrophic consequences that could ensue from a nuclear confrontation. This concept of deterrence is foundational to national security strategies, especially during times of geopolitical tension, as it promotes stability by ensuring that the consequences of war would be unacceptably high.

In the context of international relations, countries with nuclear capabilities aim to maintain a balance of power, which discourages military actions against them. This objective contrasts significantly with other potential purposes like promoting international trade, conducting scientific research, or supporting humanitarian missions, which do not directly relate to the primary role of nuclear arsenals in national defense.