Arendt was certainly critical of the nation-state version of Israel, & of both the Biltmore & Atlantic City programs, the latter of which failed to acknowledge even the existence of Arabs in Palestine.
Still: "I don't belong to any group. You know the only group I belonged to were the Zionists," she said in reply to Hans Morgenthau about her political affiliations.
Many of her predictions in the essay she wrote for Commentary, To Save The Jewish Homeland: There is Still Time, were prescient. Although she believed in a Jewish homeland in Palestine, she thought partition would lead to endless war, that Israeli government would perforce become increasingly totalitarian, that Zionist Jews would gradually adopt a separate identity, to name just a few.
Still, she acknowledged that assimilation, at least in Europe, had been a disaster for Jews.
For me, ironically, it was an off-hand comment by Arendt in Eichmann in Jerusalem that suggested the ability to make war effectively isn't the sine qua non of civilization. I wrote about it. Yet, look at Israel. She even uses the word "Sparta" in her Commentary piece.