there is a limit to how much interest can be on loans and how much of a person's/country's income can be extracted to pay for one.

in most countries in debt that debt has been paid of many times over. (the case of nigeria is perfect). they are in something amounting to 600% interest on their debt which they have already paid over a few times.

you can argue illegitimate debt in this instance or if it is starving said/person country by taking a high percentage of income. a good lawyer and accountant would do that for you. but refusing to pay is fine as there is no legal right to take action on that debt. mobsters and loan sharks don't operate within the law so don't count (but then again neither does america).

anyway back on topic. this kind of knowledge is freely available anyway. the complexity's of making stuff like sarin and an atom bomb are what make it stupid to teach it. explosives thought are easy to make and are best for guerilla war.