You could say the same exact thing about AIPAC. It’s also a membership-led and membership-funded organization where the vast majority of it’s funding coming from private donations… yet somehow I don’t think you’ll have the same reaction to them being foreign assets. The reality is that both of these organizations advance the interests of foreign governments over America’s, only difference is that Israel is a US ally and the countries that the DSA chooses to align itself with are American adversaries.
There’s a distinction between war and terrorism. Terrorism is done by non state actors, wars are done by states. For example, there’s a very big difference between the democratic government of the Philippines voting to fight ISIS in their southern islands, and some random ISIS terrorist trying to kill the Filipino president to intimidate non muslim candidates from running for president.