We focus most of the attention on how Iran is a threat to Israel and therefore a destabilizing force in the region

Flip the equation and, from Iran's perspective, I can see how Iran would consider Israel and the USA to be a threat to them. Israel is enacting policies that are as fundamentally extreme as those of Iran, and they are (despite recent posturing) unconditionally supported by the most powerful military force the world has even known. Although I would not welcome such a development, I cannot see why Iran wouldn't move forward with nuclear capability.