A blast from the past; Obama encouraged nuclear proliferation

Generally speaking since 1945 the international community has tried to restrict the number of countries that have nuclear weapons based on the idea that the fewer countries with such weapons would reduce the risk of nuclear war.

When the Soviet Union collapsed Ukraine was left with a massive nuclear arsenal.  In order to get Ukraine to give up those weapons and denuclearize Russia, England, and the US promised that Ukraine's territorial integrity would never be changed; ie if someone one invaded Ukraine those countries would come to Ukraine's defense.

Yet when Russia invaded Ukraine in 2014, seizing Crimea, Obama refused to even provide lethal military aid to Ukraine.

Given that Ukraine knew that if they'd kept their nuclear weapons Putin wouldn't have invaded the lesson every country in the world learned is that US commitments are worthless.  This in turn makes it clear to countries that having their own nuclear deterrent is the only thing they can count on.

When countries like South Korea, Japan, and Poland look at their security they now know that leftist presidents like Obama can't be counted on and hence in the calculus of deciding whether or not to go nuclear the results are now biased towards getting the bomb.

By refusing to uphold the US's commitment to Ukraine Obama ensured that more countries are likely to be looking seriously at acquiring nuclear weapons.

That's why Obama's working hard to ensure that Iran could develop the Bomb, albeit after he was out of office, isn't that shocking.  Clearly Obama wasn't that concerned about nuclear proliferation when stopping it would have interfered with his foreign policy priorities.