...no one is above the law, no one is above the reach of US sanctions

A hypocritical statement if there ever was one since US sanctions can be considered a violation of international laws. I'm sure the only reason they don't impose them from the UNSC is because they could (and likely would) be vetoed by other members (and because the US is imposing sanctions on UNSC members.

The legality of economic sanctions is contested, with debates varying based on the scope of the sanctions, their goals, their effects, the authorities under which they are imposed, and many other factors.

One school of thought holds that it is only the United Nations Security Council that can legally impose sanctions (with that power derived from Chapter VII of the UN Charter). Unilateral sanctions, or multilateral sanctions not endorsed by the UNSC, in contrast, violate the principle of state sovereignty and undermine the international rule of law. According to former UN Special Rapporteur Idriss Jazairy, “the resort by a major power of its dominant position in the international financial arena against its own allies to cause economic hardship to the economy of sovereign States is contrary to international law, and inevitably undermines the human rights of their citizens.”

Economic sanctions imposed unilaterally by the US may also violate the Charter of the Organization of American States, to which the US is a party. Articles 19 and 20 of the Charter state:

"No State or group of States has the right to intervene, directly or indirectly, for any reason whatever, in the internal or external affairs of any other State. The foregoing principle prohibits not only armed force but also any other form of interference or attempted threat against the personality of the State or against its political, economic, and cultural elements. … No State may use or encourage the use of coercive measures of an economic or political character in order to force the sovereign will of another State and obtain from it advantages of any kind."

Other arguments against the legality of economic sanctions are based on their impacts. Given the significant harm to civilian populations, many economic sanctions can be said to violate international human rights law and treaty obligations, such as the Vienna Declaration and Programme of Action and several UN Human Rights Council Resolutions. Further, as described by Jeffrey Sachs and CEPR’s Mark Weisbrot, “both the Hague and Geneva Conventions, to which the US is a signatory, prohibit collective punishment of civilians. Although these treaties apply only during wartime, UN human rights experts have argued that it does not make sense that civilians should only have this protection during situations of armed conflict.”

On the 75th anniversary of the signing of the Geneva Conventions, in 2024, 40 legal groups and 200 individual lawyers, including top scholars, sent a letter to President Biden calling on the US to end the use of broad unilateral sanctions, which they consider to violate international law, and amount to “collective punishment.”

To the extent that particular sanctions violate international law, they erode international legal norms and undermine aspirations toward a rules-based international order.

Many US sanctions rest on shaky foundations under domestic law as well. Most are imposed under the IEEPA, which requires declaration of a national emergency regarding an “unusual and extraordinary threat … to the national security, foreign policy, or economy of the United States.” In many cases, such a claim — that, for example, the political situations in Venezuela or Zimbabwe somehow constitute an “extraordinary threat” to US national security — has little to no basis.

US rules-based international order is when you can pick and choose which laws apply to your own actions.