I am due to marry for the first time, and intend to make a pre-nuptial agreement with my Israeli fiancee, before we marry and I relocate to Israel as I have substantial pre-marital assets. I made a will in the USA, where I live,several years ago,before I meet my fiancee, in which my estate is shared equally between my brothers and my parents.Should I update it, as well as entering into a pre-nuptial agreement?

Firstly, you need to reassess the situation, and decide whether, as a person who is due to marry shortly, and even have children, your current  will, made before you married, still represents your true wishes, should you die. If you think it may not, then you could  make a new will, in which you include your future wife, and future children,as well as your siblings and parents, address various scenarios, and even make conditional bequests, relating to the length of your marriage, whether you have children or not, and whether your siblings and parents are alive at the time of your demise, etc.

If you do nothing, and die, while the beneficiaries under your existing will (your siblings and your parents)  will may act to gain probate (an order enforcing the instructions of the will), your wife/widow, may object to the probate application, and claim rights as  your common law  heir, under Israeli law, together with any children you have. By cancelling your existing will and making a new one, you will be clarifying the situation, and possibly preventing a dispute concerning your estate, should you die.