Can grandparents living outside Israel bring legal action to see their Israeli grandchildren if their ex-daughter-in-law objects?

Yes - and they can be successful if the relationship is held to be in the children's good, even if their mother objects . Under Israeli law  grandparents can  bring adversarial action to see their grandchildren, if a preliminary dispute resolution process fails . Usually a social worker is appointed to make a report and recommendations on whether meetings and contact with the minors is in the grandchildren's best innterests.

Our law practice successfully represented British grandparents in their legal battle to re-establish meetings with their teenage grandson which  his mother, their former daughter-in-law, with whom he lived , had stopped. The court appointed a social worker to make a report and recommendations. and heard the teenager's views as well as meeting with the parties,and hearing their claims . At a hearing at Jerusalem Family Court in April 2018 the parties  agreed to accept the report 's recommendations,  to re-establish the visits in Israel, and after authorizing their consent, it also ruled  that from 2019, the grandson could visit the grandparents in England, during the Summer , instead of Israel, bringing forward the date recommended for this, by the social worker, after oral pleadings.