> I am not aware of any ad network policies that approach the subject of "what is true" or "what is propaganda".

From the article:

> The ad mimicked a UN website but actually linked to an Israeli government page

You don't need to judge wether the information linked is true to judge whether the ad misrepresents what users will find behind the link. If Pepsi made ads using a fake Coca Cola website to redirect to pepsi products, they would run afoul of google's policy regardless of your opinion on Pepsi.

Whether you think this enforcement choice is legitimate or not, as you said, it's clearly an editorial choice from google, and there's no reason it should escape public scrutiny and, if needed, regulation.