You will find Islamists using terms like “the international system”, without having any concept of what it means; to them it just refers to an abstract reality of Western domination over the Muslim world.
If we can lift our heads for a moment above the perimeter of our own habitual provincialism and tunnel-vision, we would see that the “international system” is dominating 99% of the world’s peoples, Muslim and non-Muslim; oppressing and exploiting, dispossessing and enslaving nations and sabotaging governments from Latin America to Africa, from Southern and Eastern Europe to the Middle East; and indeed, even within the United States and the European Union.
It is a system run by the global owners of capital, the super-rich 0.1% of the population, by means of multinational corporations, banks and international financial institutions; enforced whenever necessary by the militaries of collaborating subordinate countries in the form of ad hoc coalitions or standing alliances like NATO.
What they are doing to us, they have done, and are doing to others, and have done and are doing to each other.