The document discusses energy sanctions against Russia, Iran, and North Korea. It explains that sanctions are used by the US to enforce laws and policies, and are intended to maximize economic impact on the target country while minimizing damage to US economic interests. Sanctions can be imposed by the US alone or internationally. Russia has faced sanctions due to human rights violations, while Iran is questioned for supporting terrorism. It is difficult to determine the true economic impact of sanctions, as other factors like falling oil prices also influence economies.