Just when there seemed to be a consensus inside Israel concerning a two-state solution to the conflict, we seem to be in danger of losing it altogether. The growing number of settlement-related facts on the ground, the harder it is to make a clean territorial cut, evacuate hundreds of thousands of settlers and demarcate a border of ethnic and national separation.

Drawing borders is a pre-requisite for implementation of a two-state solution. The two alternatives, a single bi-national state and continuation of occupation, do not require any form of territorial separation.

There are two options for the demarcation of borders. Either there is an automatic withdrawal to the green line (the armistice line separating Israel from the West Bank since the Rhodes agreements of 1949), or the green line serves as a point of origin from which necessary changes are made, reflecting the situation on the ground today and the many changes that have taken place during the 43 years since the Six-Day/June 1967 War.

Any such changes have to be part of a bilateral process of negotiation and boundary demarcation. They cannot be one-sided or imposed by one side (Israel) upon the other, as is the case with the separation barrier/fence. The latter has deviated from the green line in one direction only--inside the West Bank, effectively annexing territory to Israel in an attempt to retain Israeli settlement blocs under future Israeli control and sovereignty.

The green line has never been a very effective boundary, even in the pre-1967 era. It came into being as a result of pressure of time and the realities of a ceasefire following the 1948-49 War of Independence/Naqba. In the 43 years since 1967, it has remained a de jure administrative boundary between Israel and the West Bank, but it has been transgressed in many de facto ways, not least the blurring of the line in the center of Israel, the building of roads crossing the line and the construction of Israeli settlements inside the West Bank but in close proximity to the line itself. It is the latter that, Israel claims, should be annexed under a future peace agreement. A simple stroke of the cartographer's pen would effectively reduce the number of settlers and settlements that have to be evacuated under a peace agreement.

In principle, such annexations have been rejected by the Palestinian Authority. But this long-standing position has began to change in recent years, with the acceptance by some that the difficulties Israel would encounter in evacuating the entire settler population are of a magnitude that may deter it from implementing territorial withdrawal. As an alternative it would be acceptable to implement a process of territorial exchange between the two sides, through which Israeli territorial demands inside the West Bank would be compensated for by an equal amount of territory being transferred from inside Israel to the Palestinian state.

The basis for such a territorial exchange would be 1:1--a dunam for a dunam--so that the Palestinian state would end up with exactly the same amount of territory as that encompassed within the present boundaries of the West Bank and Gaza Strip. Territorial exchange would only take place along the course of the green line, ensuring territorial contiguity for both sides, without any exclaves, enclaves or extra-territorial anomalies such as territorial corridors.

There are areas in close proximity to the green line inside Israel that could effectively be swapped. In particular the southern section of the green line, running from the Lakhish region and along the southern Hebron foothills, is an area of relatively little Israeli/Jewish settlement on both sides of the green line. Territorial exchange there would result in minimal dislocation for the region's residents, while at the same time enabling contiguous lands to be attached to the Palestinian State.

In the central and northern sections of the green line an exchange is more difficult to implement because of the greater population densities in close proximity to the existing boundary. But herein lies a much greater problem. It is precisely in the northern sections of the region where the towns and villages located near the green line are populated by Palestinian Arab citizens of Israel. The idea that territorial exchange could take place in this area, to include such places as Um al-Fahm and Baqa al-Gharbiye, has been proposed by right wing groups in Israel who, while opposing in principle all notions of territorial withdrawal, have stated their support for territorial exchange only if it brought about the "silent" transfer of as many Arab citizens of Israel as possible to the future Palestinian state. This, they argue, would not require any dislocation since people would remain in their homes.

But it would result in an enforced change of citizenship for a population that has repeatedly expressed its intention to remain inside Israel and has rejected proposals aimed at transferring it to the Palestinian state. The proponents of such an argument point to the many incidents of boundary redrawing that took place in Europe following World War I, where populations underwent citizenship transfer against their will while remaining in situ in their villages and homes. Beyond the immorality of such a scenario, this would send the wrong message to the Arab citizens of Israel. After all, it is continually argued that they will be able to undergo greater integration into Israeli society and will no longer be perceived as constituting a fifth column inside Israel proper only if and when the Israel-Palestine conflict is finally resolved.

Leaving the populated areas aside, there is ample land available in other parts of the region for territorial exchanges of up to eight percent on either side of the line. The resulting border would be no more tortuous and meandering than the original green line and would take into account existing realities on the ground today. True, this would effectively legitimize some of the Israeli settlements retroactively. But if it were to enable the implementation of an agreement with greater ease, and if both sides were to feel that their territorial claims had not been unilaterally usurped by the other, then there is nothing sacred about the green line that renders it the only default boundary for a future Palestinian state