What is the main ethical concern regarding the use of nuclear weapons?

The main ethical concern regarding the use of nuclear weapons is fundamentally rooted in the potential for mass civilian casualties. Nuclear weapons possess an unparalleled destructive capability that can obliterate entire cities and indiscriminately kill large populations, including non-combatants. This raises significant moral questions about the justifications for their use in warfare and the responsibilities of nations to protect civilian lives. The sheer scale of human suffering and the long-term environmental impacts, including radiation exposure, add to the ethical dilemma, compelling consideration of humanitarian principles over strategic military objectives.

The other aspects, while relevant in discussions about nuclear arms, do not encapsulate the ethical implications as directly. The cost of development and ease of transport may affect decisions to pursue or utilize nuclear weapons but do not carry the same moral weight regarding the consequences of their deployment. Similarly, while the risk of international relations is a critical factor in defense strategies, it is the prospect of mass civilian casualties that resonates most starkly with ethical considerations.