But only if you already developed technology needed to survive on mars and have an industrial base not touched by those nukes. Having a self-sustaining outpost

But only if you already developed technology needed to survive on mars and have an industrial base not touched by those nukes. Having a self-sustaining outpost somewhere other than earth is valuable not only for its own sake, but also due to the developed technology and industry and infrastructure implied by its existence. If tomorrow you suddenly need a huge fleet of fully reusable ships for some reason, the right time to start working on them was 20 years ago, or as soon as basic science and technology level allow. There are also political risks (we are all too close to each other).