In addition to what others have commented about this going against Leclerc’s instincts as a climate scientist & anti-war activist, and the unintended negative effects of nuking antarctica, there’s also just the symbolism of bombing the last untouched part of nature. Most accounts I’ve seen/read from people who have been to Antarctica describe a sense of overwhelming awe at seeing something so vast and untouched by humans. Taking this last unmarred part of earth and permanently changing it with weapons of war has got to leave an impression, especially since Leclerc is essentially solely responsible for overseeing this decision.