I'd take it that the "International" in "Internatuinal Solidarity Movement" has the same implication as it has in regard to the International Brigade in the Spanush Civil War - meaning that it is where people from other countries can get involved in a struggle. I can't see that the term would imply anything particular about its leadership structure.

And that quote where it says that the ISM "recognize(s) the Palestinian right to resist Israeli violence and occupation via legitimate armed struggle" - surely the crucial word is "legitimate", which would exclude terror attacks on civilians. Given that proviso, while it is not a pacifist position, it is one which is actually consistent with international law. After all, the occupation of the West Bank and Gaza by Israel is in breach of numerous Security Council resolutions.

The underlying factor beneath the drifting into specifics in this thread is that opposition to Israeli policies, especially occupation and repression, but also including the denial of a right of return to Palestinians, in no way implies anti-semitism. However one of the effects of the claim that opposition to Israel does imply anti-semitism is to make it easier for anti-semitism to crawl back into the light. It blurs the distinctions, and that, I would suggest, is one reason why the claim is often made.