A long running complaint I have articulated on this site is my beef against the list of countries supporting terrorism. The complaint long predates the Trump Administration and goes to the fact that the U.S. government, no matter who is running it, just treats the list as an American shit-list rather than the product of a factual inquiry whether a foreign government is, in fact, supporting acts that meet the definition of terrorism. Countries that fall out of favor with the U.S. (especially, but not entirely, Muslim countries) will find themselves on the list. Countries that are in America's good graces will avoid being listed. The fact that Saudi Arabia has never been on the list speaks volumes about the list's utter lack of credibility.
Historically, the designation of terrorist organizations, while still influenced by politics, has been a little better. Well, no more! Now that Trump has designated the Islamic Revolutionary Guard Corps as a terrorist organization, it has, for the first time, labeled a unit of a foreign military as a terrorist organization. No matter how bad the IRGC is, it is a blatantly ridiculous designation because the definition of "terrorism" means an action by a non-state actor. Terrorism means violence by people who are not in any country's official military. The U.S. army can't commit terrorism, not because it can't blow up a building, but because its official job as a military organization is to blow up stuff and that gives it a level of legitimacy that non-state groups don't have. What makes something terrorism is not just the violence or the harm it causes to civilians (both of those things official militaries regularly do), it is the fact that the people doing the violence are not soldiers. Labeling the IRGC a "terrorist organization" violates the very definition of "terrorism."
You might say that this is just a semantic issue. And it is! But semantics are important when we try to make sense of the world. The state-actor vs. non-state-actor distinction is a big deal. It is about the legitimacy of terrorism. If violence is terrorism just because we don't like the people doing the violence, then it won't be long before the U.S. military finds itself classified as a terrorist organization by others. In the long run this undermines the legitimacy of every country's military and it will make "terrorism" seem more legitimate, or at least just as a matter of opinion rather than an actual thing.