Why has Iran resolved to ensure crippling sanctions and exist as a pariah state in the international system? Is the Iranian leadership rational for seeking nuclear weapons?

As Joe Biden begins his term as President of the United States, he is left with the question of how to best tackle the dispute between the United States and Iran over the Iranian nuclear program and the JCPOA. To best understand how the Biden administration ought to proceed, it is important to first understand the legal context behind the final actions of the Trump administration and what strategy they wished to pursue.

Currently, the United States theoretically maintains the ability to defend Taiwan using conventional force, thus potentially avoiding the need for an all-out nuclear war with China over the fate of the island. What happens if the status quo shifts and nuclear threats are the only way to protect Taiwan?