But in your example, the unstated premise is that the opposition leader is not in fact a terrorist, so his killing is wrong.
In the case of Hamas, they are in fact terrorists. So the analogy fails.
In the case of Hamas, they are in fact terrorists. So the analogy fails.
My point is that if Russia were to conduct a bombing on US soil, regardless of who it was targeting, the response would be severe and the reasonable onlookers would not blame the US for being "upset" about it. Yet that is exactly what Israel has done to Qatar.
Sure, China or Russia can and will label political opponents "terrorists" to justify persecution against them. Their goal is to destroy the international consensus, so that "terrorist" becomes a purely subjective label. By equating Israel's bombing of an actual terrorist group with Russia's persecution of a fake one, you are supporting Russia in this effort.
Instead, you should equate Israel killing Hamas leaders with the US killing Bin Laden, coalition forces bombing ISIS in Iraq, France bombing islamists in Mali, etc.