Realizing that international affairs are much more complicated than runaway trains (though many times they're not all that dissimiliar), I thought I'd pose a few more realistic moral quandries to you guys and gals. Here's the first:

1) The leader of a small Asian country holds a repressive iron grip on his people. He has a million-strong army, possibly a nuclear weapon or two, and has withdrawn from all international treaties regarding nuclear control in order to more aggressively pursue a larger nuclear arsenal. Malnutrition and starvation are rampant in this country. There are virtually no civil rights, and dissenters are sent away to "reeducation camps" where the life span is in months rather than years.

You are the ruler of a large, powerful country, both economically and militarily. You have tried to deal diplomatically with this country, exchanging food and fuel aid for disarmament, but the Asian country as reneged on all agreements thus far. You also suspect that the bulk of aid is not going to those who need it most, but to government elites and the massive military infrastructure. If you give more aid, it will most likely continue to be used in the same manner. If you enforce economic sanctions, it might very well provoke a military response, and would most likely only worsen conditions for those already in distress. If you do nothing, millions will continue to starve, suffering either death or a host of conditions related to severe malnutrition. Millions more in neighboring countries, or perhaps your own could very well die from the massive firepower of a growing nuclear arsenal. Knowing that an attack could very well lead to great bloodshed, is it morally permissible for you to invade this country and depose this leader?