Tightened barriers are the prime measure used by Yitzhak Rabin, the Israeli Prime Minister, against the Palestinian workforce to protect his citizens inside Israel proper against further Arab violence. The 'closure' may provide Israelis with some limited reassurance, but will have little security value.
If the closure is indeed 'indefinite', as Mr Rabin has threatened, despair and alienation will deepen in Gaza and the West Bank, and Hamas, the Islamic Resistance Movement, may well reap the rewards. Palestinian economists predict that the new and poor Palestinian authority may collapse.
After Israel seized the occupied territories in 1967 it squeezed the Palestinian economy and forced the Arab workforce into low-paid jobs in Israel. After recent closures, the number of Arab workers in Israel had already dropped to about 60,000. By barring the workforce entirely this week, Mr Rabin has cut off dollars 1.2m ( pounds 800,000) a day in Palestinian earnings.
'I cannot imagine how we will cope,' said Samir Abdullah, a member of the Palestinian committee formed to oversee development in the self-rule areas.
'It will be impossible for us to employ these workers, even if we spent all the money now coming in from the donors.'
There must be 'separation' between Arab and Jew, says Mr Rabin. But, as has been proven many times before, it is impossible to seal off the occupied territories effectively.
The security cordon can always be breached by a determined fanatic, using stolen cars and false identities. Exceptions always have to be made, and previous closure orders have always been swiftly eased under pressure from Israeli employers, particularly in the construction and farming industries.
Although Israeli unemployment is 10 per cent, Mr Rabin this week granted permission for an extra 15,000 foreign workers to replace Palestinian labourers.
The fact that nearly a million Arabs live as Israeli citizens inside Israel complicates the security calculation, and the 150,000 Arabs in East Jerusalem are, as in the past, unaffected: to impose physical barriers would be to admit Jerusalem is a 'divided city'. Instead the closure severs East Jerusalem from its West Bank hinterland.
Some Israeli doves say the new talk of 'separation' is a sign that Mr Rabin wants Jewish settlers to move back to Israel proper. Then the West Bank and Gaza could be sealed off. According to this analysis, he is, in effect, paving the way for a full Palestinian state, including the West Bank and Gaza.
Palestinian analysts point out that one key element of the autonomy plan which is scotched by the closure is the idea of linking Gaza to the West Bank by 'safe passage' routes running across Israel.
While in the long term Mr Rabin clearly envisages removal of settlements near centres of Arab population, he has said little to support the idea that 'separation' would mean a Palestinian state. Rather he appears to envisage a cantonised and economically weak West Bank, dependent on Jordan, while Gaza would become dependent on Egypt. Mr Rabin appears to see the closure as an instrument to that end, hoping the Palestinians will tolerate their new economic hardship.Reuse content