Whether one side or the other has in the past acted immorally is irrelevant. You don't win the argument by saying "America has done bad things too", as if that should persuade it to change its behavior. It's a category error; nothing but ineffectual emotive fluff. You'd have more traction arguing that sanctions are, in fact, not in America's long term best interests.
In reality, beneath the surface, is a complex web of relationships and competing/aligned interests.
A good example is the Israel-Palestinian conflict. It may seem like an Israel-Arab conflict, but many Arab countries are aligning with Israel to counter the Shiite threat from Iran. But those same Arab countries can’t abandon the Palestinian cause either. So they walk a tightrope of tacitly supporting Palestine, often hollow public statements about the “on-going fight for a Palestinian state” all the while strategizing with Israel on how to contain Iranian influence. They can’t support Palestine 100% because that would mean severely weakening themselves with regards to Iran.
One can argue that’s two faced and they should be ashamed of partnering with the enemy of a group they support, but in reality every country does it. It’s about practically protecting your interests. And sure you might seem like you flip flop in your statements, but alliances and enemies are created and disappear all the time.
The problem with that angle is that without caring about morals, military invasion is probably better for America's interests than sanction relief.
