The Holy Land may be the cradle of Judaism, Christianity and Islam – the three Abrahamic faiths that share much in common – but Israel has preferred to draw on a tradition that imagines the region in terms of a clash of civilisations.

Theodor Herzl, the father of Israel’s national ideology, Zionism, averred that a Jewish state should act as “a rampart of Europe against Asia, an outpost of civilisation as opposed to barbarism”. On this view, Israel is on the fault line between a Judeo-Christian west and the barbarian hordes of the Islamic east.

The idea of a clash has played out most obviously in Israel’s repeated wars against its Arab neighbours, its threatening posture towards Iran, and its interminable occupation of Palestinian territory – heavily subsidised both directly and indirectly by the United States and Europe.

But Israel also wanted to exploit this model inside its own territory, among its citizens. Decades of institutional and systematic discrimination and internal repression of its 1.5 million Palestinians who have citizenship have been justified to the Jewish majority in these terms.

This is the context for understanding the announcement this month by Israel’s prime minister, Benjamin Netanyahu, of what is being called innocuously a “forum” between the government and Israel’s Christian Palestinians.

Its troubling goal is to end the exemption Christians in Israel have enjoyed from serving in the military.

On a practical level, Mr Netanyahu hopes that Christians can help enforce Israel’s illegal occupation of their kin in the West Bank, East Jerusalem and Gaza. But this move is not really about swelling the army’s ranks.

Both Christians and Muslims are excluded from Israel’s military service. Individuals can seek a waiver on this exclusion and each year a few do so: around two dozen among Christian Palestinians and small numbers of Muslims, mostly from the Bedouin community.

If Christians are made to serve, they will join Israel’s tiny Druze community, which has been conscripted since the 1950s. That will then leave only the largest section of Palestinian citizens – Muslims – excluded.

The role of the Druze is illustrative. They have few benefits to show for decades of army service, even though Israel has treated them as a national group separate from other Palestinian citizens. They even have their own school system to inculcate beliefs that the Druze and Jews are historic allies.

Keen to prove their loyalty to the state, the Druze are much feared in the occupied territories, where they are seen as even more brutal than their Jewish comrades.

If Mr Netanyahu succeeds, he will achieve an important task, reversing the long-term commitment of Christians and Muslims in Israel to unity. The two communities have set up joint political institutions and secular parties that cut across the sectarian divide.

In recent years their identity as Palestinians has strengthened – not least because Israel has defined the core Israeli identity in terms of belonging to the Jewish people.

Mr Netanyahu would rather turn the clock back to the 1950s when the native population were known simply as “the minorities”, and expected to identify as sectarian groups. The aim was to exploit these differences to keep each sect weak, isolated and, ideally, feuding.

Now Mr Netanyahu sees a chance to use military service as a vehicle for implementing a policy of divide and rule.

The idea has been brewing for decades, but was unrealisable because Israel could not find, as it did with the Druze, a Christian religious leader willing to cooperate. It now has one in the figure of a senior Nazareth cleric, Jibril Nadaf.

Mr Nadaf gave his blessing to a conference last year staged by the defence ministry to promote military service among the Christian scout movements. Community leaders who denounced him have been interrogated by the security services on suspicion of incitement.

Israel is trumpeting its success in tripling the number of Christian teenagers drafted over the past year. But the numbers are still small.

Israel has sought to capitalise on this moment by highlighting to Christians the supposed dangers posed by the Arab Spring. Israeli officials suggest that the growing power of Islamic movements is a warning that the region’s Christians need to ally with the Jewish state.

Mr Nadaf now speaks in similar terms. He recently said: “Our goal is to protect the Holy Land and the State of Israel.” Only Christians helping Israel, he added, were “following the path of Christianity”.

Israel’s fingerprints are not hard to spot on these developments. Last month a new political party was formed in Nazareth running on a joint Christian-Jewish ticket and advocating conscription for Christians. Its founder is the brother of the defence ministry’s adviser on Christian affairs, Ehab Shilyan.

This dangerous meddling in the delicate relations between Christians and Muslims inside Israel could easily lead to violence and bloodshed. But Israel is unlikely to care when the benefits are manifold.

Palestinian Christians have been key figures in the fight for equal rights inside Israel, a struggle that has deeply embarrassed Israel by threatening to expose the structural inequality required by a Jewish state.

Israel would prefer to weaken this kind of internal secular Palestinian politics, leaving the field to the Islamic extremists.

Christians in Israel have also been powerful advocates for international campaigns against Israel, using their connections to promote the boycott, divestment and sanctions movement building among overseas church groups – what Israel terms “de-legitimisation”.

Repositioning Palestinian Christians on Israel’s side would take the wind out of that campaign.

But perhaps most importantly, Israel would prefer that Christians reject the Palestinian variant of liberation theology and adopt the Christian Zionism that dominates in the US, Israel’s chief sponsor.

The Christian Zionists believe Jews and Christians are heading towards an apocalyptic showdown with Islam.

All of this is designed to corral Israel’s Muslim population into a corner, creating a much cleaner narrative for Israel in which Jews and Christians are brothers guarding the ramparts. But more likely Israel risks ensuring its clash of civilisations thesis becomes a self-fulfilling prophesy.