In his article for Foreign Affairs David Cohen talks about the Trump administration's policy towards sanctions. He talks about how the conditional sanctions the Trump administrations has placed on Iran and now Venezuela will be ineffective because the changes the administration is trying to coerce will essentially mean regime change for the two nations. Cohen goes on to state that these will be ultimately ineffective because the relative cost of the sanctions is lower than the cost of losing power. This means that the leaders of Iran and Venezuela are more willing to bear the pain of the sanctions than lose the regime.
This goes along with the lesson we had on sanctions in a couple of ways. First we learned that sanctions are used either as a method of deterrence or coercion. This means that the sanctions inflict financial and economic pain to make the target of the sanctions take or not take an action. These sanctions are meant to cause political changes that will in essence mean a change of regime which is why they will fail. They are effective in causing pain; however, there is not enough sanctions in the world to make it worth losing power.