Obituaries for the two-state solution to the Israeli-Palestinian conflict are appearing with increasing regularity, with examples including recent pieces in the Guardian by Rachel Shabi and Ghada Karmi. Among supporters of the Palestinian national struggle, those now calling for a single bi-national state are clearly in the ascendency, but the view is not unanimous. People such as Norman Finkelstein and Noam Chomsky continue to advocate the establishment of two states along the 1967 borders "subject to very minor and mutual adjustments". The disagreement is over tactics and analysis, rather than politics or principle, but it is no less significant for that.

The case for a single, bi-national state is now reasonably familiar. Israel's illegal settlements are so entrenched that uprooting them to make way for a viable Palestinian state has become impossible. We should therefore call instead for a single, democratic state in the whole of the former British Mandate for Palestine.

But the logic is incomplete. Declaring the two-state solution unrealistic does not, by itself, make self-evident the greater feasibility of one bi-national state. The latter would entail the end of Israel, and of Zionism, as we understand those terms today. Is this really a more likely scenario than the colonial infrastructure in the occupied territories being dismantled? Recent polls showing alarming levels of racism in Israeli public opinion, reflected in the new hard-right alliance between Likud and Yisrael Beitenu, suggest a polity that is not currently minded to dissolve itself under any amount of political pressure.

A map produced by Palestinian negotiators showing how land could be split between Israel and Palestine.

Obstacles to the decolonisation of the Palestinian territories are certainly real, but should not be overstated. The settlements themselves take up very little space. It is the settlement blocs which dissect Palestinian territory, seize key natural resources and render unviable an independent state on the land that remains. Palestinian negotiators have produced detailed maps showing how, with those obstacles largely removed, an exchange of land equivalent to 1.9% of the West Bank could leave 63% of Israeli colonists in situ, and the Palestinians with a contiguous, viable state (black areas to be annexed to Israel; orange areas to the future Palestinian state – Source: Palestine papers)

The offer is a generous one, given that Israel's colonisation of the territories is illegal, as confirmed by the International Court of Justice in 2004. Ten years ago, the Arab League offered Israel full recognition in exchange for its withdrawing to its legal borders and agreeing a just solution for the Palestinian refugees, a formula agreed by the Palestinian leadership but rejected by Israel. While formally opposed to such a settlement, even Hamas has indicated that it would accept it if ratified by the Palestinian people who, though despairing of their situation, continue to favour a two-state settlement. The problem is less the two-state solution than Israel's rejectionist stance, which benefits from crucial backing, or acquiescence, from its patron in Washington, as well as the EU states. Vigorous and well-targeted public pressure on Israel and its western allies is required so as to change the strategic calculus for Israel, and render it in its own interests to withdraw to its legal borders.

For advocates of the Palestinian cause, the alternative to pressing for the two-state settlement, a difficult objective which still retains a decent amount of support, is to pursue a far more difficult objective that enjoys considerably less support. The result would be to reduce effective pressure on Israel, which in turn would allow it, as Chomsky stated in response to questions I put to him via email, to "continue with its current policies: tak[ing] what is valuable in the West Bank, perhaps 40-50%, including very few Palestinians", while consigning the rest to "unviable cantons" with the option to "rot, or leave".

There would thus be no "demographic problem" setting the scene for an anti-apartheid struggle. Meanwhile, "Gaza will remain a prison, separated from what remains of West Bank Palestine in violation of the Oslo accords". In short, without effective pro-Palestinian advocacy based on a realistic appraisal of the situation, Israel will be free to maintain the status quo indefinitely. Conversely, the most practical route to a bi-national state may lie in securing a modicum of justice and peace as soon as possible through a two-state settlement, thus establishing the conditions most likely to lead, through dialogue and consensus-building over the longer term, to a more enduring bi-national state.

This is the path favoured by Chomsky, who notes that "for 70 years, I've advocated a bi-national settlement. However, I have advocated achieving that objective, not merely talking about it. That means that it is necessary to pay attention to real-world circumstances, and… sketching a feasible path from here to there. Barring that, it's like saying 'let's have peace in the world.'"

• This article was amended on 2 November 2012. The author originally wrote of public pressure on Israel and its western allies being required to render a withdrawal from the illegal colonies in Israel's best strategic interests. The word "render" was changed in the editing process to "effect". This sentence has now been reworded to reflect the author's original intent.