Will an Israeli court divide my US 401(k)?

Yes — the court determines the marital value and orders how it is to be divided. However, actually splitting the 401(k) account still requires a Qualified Domestic Relations Order (QDRO) issued by a US court, because Israeli court orders are not recognized by US plan administrators. The Israeli court can order your spouse to cooperate in obtaining a QDRO and can hold them in contempt if they refuse.