The Palestinians are the victims of the cruel geopolitics of a region in which foreign powers have always played a decisive role.

Britain, the pre-eminent Western power in the region in the first half of the 20th century, was no friend to the Palestinians and it is still no friend today. Leaders of both main parties have tended to side with the Zionists in this bitter, bloody, and apparently intractable century-old conflict.

Duplicity and double-dealing were the hallmarks of British policy towards Palestine from the beginning.

In 1915, Britain privately promised Hussein, the Sharif of Mecca, to support an independent Arab kingdom after the war if he would mount an Arab revolt against the Ottoman Empire.

The venerable Sharif kept his side of the bargain but Britain did not. On November 2, 1917, Britain issued the Balfour Declaration, pledging its support for the establishment of a national home for the Jewish people in Palestine. So Palestine became the twice-promised land.

'Classic colonial document'

In 1917, the Jews constituted 10 percent and the Arabs 90 percent of the population of Palestine. Britain had no legal or moral right to assign national rights to the tiny Jewish minority and to deny them to the Arab majority. But it was a colonial era and the Balfour Declaration was a classic colonial document.

One of the very few honest remarks on the subject was made in retrospect by none other than the author of the Balfour Declaration himself.

"In short, so far as Palestine is concerned", wrote Lord Balfour, "the Powers have made no statement of fact which is not admittedly wrong, and no declaration of policy which, at least in the letter, they have not always intended to violate."

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Among Labour leaders, Tony Blair was the most ardent supporter of Israel, with the possible exception of Harold Wilson. Blair felt an ideological affinity with democratic Israel, but geopolitics also played a part.

A major reason for Blair's utterly uncritical support for Israel was his desire to curry favour with the neo-conservative administration of George W Bush. Some of the leading neocons in the administration were Jewish and all of them were pro-Israel.

The neocons were chomping at the bit to wage war on Iraq for various reasons, one being to remove a potential threat to Israel's security.

Linking Iraq to Israel-Palestine

In Britain there was strong popular and parliamentary opposition to war on Iraq, especially within the Labour Party's ranks. To overcome this opposition, Blair linked Iraq to the Israel-Palestine issue.

There were two key issues in Middle East politics, he told the House of Commons on March 18, 2003: Iraq and Palestine. The most urgent task was to disarm Iraq from the weapons of mass destruction - which it later transpired it did not possess - and after that he pledged to do his utmost to bring about a just solution to the Israel-Palestine problem.

By stepping up settlement activity on the West Bank, Israel blocked the road to peace. It was like a man who pretends to negotiate the division of a pizza while at the same time guzzling it.

A hesitant House of Commons duly authorised the war on Iraq, which was attacked, occupied and devastated, but in the aftermath of the war, Blair was unable to make any headway in resolving the Israeli-Palestinian conflict.

By stepping up settlement activity on the West Bank, Israel blocked the road to peace. It was like a man who pretends to negotiate the division of a pizza while at the same time guzzling it.

Blair always believed that by embracing Israel, by winning its trust, third parties could persuade her to show some diplomatic flexibility. His own experience, however, should have disabused him of this notion.

Prime Minister Theresa May and her buccaneering Foreign Secretary, Boris Johnson, fit neatly into this pattern of duplicity and double standards; of indifference to Palestinian rights and uncritical support for Israel despite its systematic violation of these rights.

In their partiality towards Israel, May and Johnson are typical of the Conservative Party at large. About 80 percent of Tory MPs, including most Cabinet ministers, are members of the Conservative Friends of Israel (CFI), a well-connected, well-funded, and highly influential parliamentary lobbying group.

Some 34 out of the 74 Tory MPs who were elected in 2015 have been taken by CFI to visit Israel. For many of them this trip is just the beginning of a life-long association with the country. There is no equivalent organisation of Conservative Friends of Palestine.

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The official position of the government on the Israeli-Palestinian conflict is seemingly even-handed. Britain supports a two-state solution, which requires the establishment of an independent Palestinian state alongside Israel with a capital in Jerusalem.

Britain also regards the Israeli settlements on the West Bank as illegal and as an obstacle to peace. But this opposition to the Zionist colonial project on the West Bank is half-hearted; it is rarely backed by concrete action. The underlying reality is not one of neutrality, but one of alignment with one side in the conflict: Israel.

'Unqualified admiration'

David Cameron, when he was prime minister, described himself as a "passionate friend" of Israel and insisted that nothing could break that friendship. Theresa May evidently shares this unqualified admiration and passionate attachment to the Jewish state.

In a keynote address to the CFI's annual business lunch, May described Israel as a "remarkable country" and went on to give the reasons: "We have, in Israel, a thriving democracy, a beacon of tolerance, an engine of enterprise and an example to the rest of the world". She spoke of Israel as "a country where people of all religions and sexualities are free and equal in the eyes of the law".

She reserved her sharpest criticism for the Boycott, Divestment, Sanctions, the global grassroots campaign for Palestinian rights. This movement, she stated, "is wrong, it is unacceptable, and this party and this government will have no truck with those who subscribe to it".

READ MORE: What is the Boycott, Divestment, Sanctions movement?

May reminded her audience that Britain was entering a "special time" - the centenary of the Balfour Declaration - and she went on to deliver her wholly one-sided verdict on this infamous document.

"It is one of the most important letters in history", she said. "It demonstrates Britain's vital role in creating a homeland for the Jewish people. And it is an anniversary we will be marking with pride".

There was not a word about helping the Palestinians to create a homeland of their own on the territory that has been illegally occupied by Israel since the June 1967 war.

The prime minister's view of Israel may be dismissed as "Theresa in Wonderland" but that is the view that informs her foreign policy. It is true that last December Britain voted for Security Council resolution 2334 which condemned Israeli settlement expansion on the West Bank as illegal and as a threat to the viability of the two-state solution based on the 1967 lines.

The experts in the Foreign and Commonwealth Office had in fact played an important part in drafting this resolution and in ensuring that it would not meet with a veto from the outgoing Obama administration. But May was not too pleased with the result. Privately, she complained that she had been side-blinded by the FCO.

Kerry's 'extraordinary intervention' attacked

When John Kerry followed up on December 28 with a tough speech which was highly critical of the Likud-led Israeli government, May made an extraordinary intervention. Kerry described Benjamin Netanyahu's government as the "most right-wing coalition in Israeli history" and warned that the rapid expansion of settlements in the occupied territories meant that "the status quo is leading towards one state and perpetual occupation".

May retorted that it was inappropriate to make such a strongly worded attack on the composition of the democratically elected government of an ally or to focus solely on the issue of Israeli settlements.

Kerry had in fact covered the full range of threats to a two-state solution, including Palestinian terrorism, violence, and incitement.

May's comments may, therefore, be regarded not simply as tactless but as part of an effort to distance herself from the outgoing Obama administration on this issue and to ingratiate herself with the incoming Trump administration.

Another manifestation of this "my ally right or wrong" attitude was Britain's response to the conference convened by the French government, on January 15, in Paris with the aim of reviving the Arab-Israeli peace process and warning Donald Trump not to abandon the two-state solution. The conference was attended by 70 nations.

By [the Conservatives'] ridiculously low-level representation at the conference, Perfidious Albion wrecked the chance of a united European front on the Israel-Palestine issue.

Thirty-five countries - including the US, France, Germany, and Italy - were represented by their foreign minister. Britain was represented not by its foreign minister, nor by a junior minister, not even by its ambassador to Paris, but by a junior official in the FCO. Worse still, the official was only there as an observer with no authority to sign the final communique.

By its ridiculously low-level representation at the conference, Perfidious Albion wrecked the chance of a united European front on the Israel-Palestine issue. The move reflected a shift by the Conservative government from a barely even-handed approach towards a blatantly pro-Israeli one.

It was a snub to the Palestinian Authority and its president, and an expression of solidarity with Benjamin Netanyahu who dismissed the Paris talks as rigged and as "the last twitches of yesterday". It also sent a none-too-subtle signal of May's keen desire to turn her back on Europe and to kindle an intimate relationship with the Trump White House.

The Israeli Lobby in Britain

Another example of the Conservative government's indulgence towards Israel was its response to Al Jazeera's four-part documentary "The Lobby", which was screened from January 11-14.

Using an undercover reporter and secret filming, Al Jazeera presented incontrovertible evidence of improper interference by the Israeli embassy in Britain's democratic processes. It revealed clandestine collaboration between the embassy and parliamentary lobbyists in both the Labour and the Conservative parties to undermine their political opponents and to discredit supporters of Palestine.

"The Lobby" shows how unsubstantiated allegations of anti-Semitism were used to undermine Jeremy Corbyn, the pro-Palestinian leader of the Labour Party, and his allies.

OPINION: Anti-Zionism and anti-Semitism in British politics

It also documents the links between embassy staff and the Labour Friends of Israel and the Jewish Labour Movement, two groups who are not above invoking the anti-Semitic card to silence perfectly rational and legitimate criticism of Israeli policies.

The most shocking exposure of "The Lobby" is that of Shai Masot, a senior political officer in the Israeli embassy, discussing with a Conservative ministerial aide how to "take down" Sir Alan Duncan, the deputy foreign minister, and other pro-Palestinian politicians. Masot described Boris Johnson as "an idiot" but wished him no harm, presumably because, unlike his outspoken deputy, he does not represent a threat or a problem for Israel.

The government's response to "Shaigate" was feeble. The prime minister rejected calls from Jeremy Corbyn and MPs from all political parties, including her own, to institute an inquiry.

Johnson failed to back his deputy and rejected calls to sanction the Israeli embassy for its gross violations of diplomatic protocol. Nor did he summon the Israeli ambassador for a dressing down. Johnson told the House of Commons that to the best of his knowledge the diplomat in question was no longer employed by the embassy, that the Israeli ambassador had issued a full apology, and that he considered the matter closed.

Just imagine how the Israeli government would have reacted to evidence that a British diplomat in Tel Aviv was meddling in internal Israeli politics. When Britain voted in favour of Security Council 2334, prime minister Netanyahu summoned the British ambassador on Christmas Day for a dressing down.

He also tried to humiliate May, one of the most pro-Israeli leaders in Europe, by cancelling a meeting he was due to have with her in the Davos forum. Britain's crime was to vote for a UN resolution which conformed to official British foreign policy and commanded almost universal support.

The Israeli embassy in London, by contrast, was caught red-handed in underhand manipulation of British democratic processes. There is only one word to describe the Conservative government's conduct in this affair: cowardice.

Britain bears a heavy historic responsibility for the Palestinians' loss of their patrimony. The original sin was the Balfour Declaration. As the mandatory power from 1920 to 1948, Britain enabled the gradual takeover of Palestine by the Zionist movement.

Britain bears a heavy historic responsibility for the Palestinians' loss of their patrimony. The original sin was the Balfour Declaration.

When the Arab Revolt against Britain and its Zionist proteges broke out in the late 1930s, it was the British army which crushed it with indescribable brutality.

And when the struggle entered its critical phase in the late 1940s, and the United Nations voted for the partition of Palestine into separate Arab and Jewish states, Britain backed the bid of its client, King Abdullah of Jordan, to capture and annex to his kingdom the main area that had been allocated by the UN cartographers to the Arab state.

Abdullah and the Zionists were the only winners in the war for Palestine; the Palestinians were the losers and they were left out in the cold.

Today Israel controls 90 percent of mandatory Palestine and the Palestinians are still stateless. There are many reasons for the Nakba, the catastrophe that overwhelmed the Palestinian people. The treachery of Perfidious Albion was only one factor but not an insignificant one.

Avi Shlaim is an emeritus professor of international relations at Oxford University and the author of The Iron Wall: Israel and the Arab World.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.