One of the main planks of his election manifesto was the need to impose universal conscription and that will mean including ultra-orthodox Jews who have been exempt from military service ever since the nation came into being in 1948.
Most young Israelis expect to be called up for two years of national service yet large numbers escape the call-up if they are Haredi Jews involved in extensive religious study. This concession was granted when the Haredim were a relatively small section of society but the orthodox community in Israel has grown due to their high birth rate. They now number some 700,000 of Israel's population of six million, and there is a growing feeling they should share the burden of the country's defence needs.
But doubts have been expressed about the continuing need for conscription, which is expensive, unwieldy and not always practical. There are also concerns about how the Haredim will fit in. Not only do they pursue different religious and cultural ideologies and a general policy of dissociation from mainstream life but they frown on frivolities such as modern music, films and the internet.
There is also a political dimension. While there is support for Lapid's proposals, there is also backing for maintaining the Haredim exemption. In the last administration the orthodox party Shas was a natural ally of Binyamin Netanyahu's Likud Party but it is difficult to believe they would stay with him if he entered into a coalition with Lapid's Yesh Atid. Since the state of Israel came into being its national philosophy has been guided by "peace and security", achieved by adopting a supportive attitude towards the armed forces. Not only are they well equipped with modern weaponry, much of it supplied by the US, but there has long been a feeling it is the duty of every Israeli to participate in the defence of the homeland. In that case Lapid's instincts for inclusiveness are right but they could put him on a collision course with Israel's growing and increasingly influential orthodox community.