The Big Question: Is the bitter divide between Turkey and Armenia coming to an end?

Why are we asking this now?

Because Turkey and Armenia finally signed an agreement on Saturday to restore diplomatic ties, which Turkey broke off in 1993, and reopen the border, which Turkey closed that same year. The accord will hopefully bury the hatchet – or at least part of the hatchet – between two bitterly estranged neighbours.

Estranged by what?

Accusations of genocide, principally. Armenia says Ottoman-era Turks carried out a mass slaughter of Armenians in the First World War in what is now eastern Turkey. They insist the authorities planned and organised the slaughter, that at least 1.5 million perished and that this constitutes genocide. Turks disagree passionately, although Ankara's position has oscillated between flat denial and cagey admission that a number of people died in eastern Turkey in a series of disorganised tit-for-tat killings in which Turks were victims as well as aggressors.

And the dispute is now resolved?

Not quite, though the signing in Switzerland was a breakthrough of sorts. Under the terms of the accord, both countries have agreed to appoint experts to a joint commission that will examine the facts and – a long shot – come up with an agreed version about what happened. And in the meantime Turkish nationalists are outraged. Until recently Turkish writers who even edged towards admitting a slaughter of Armenians occurred in the First World War risked imprisonment for insulting the state. The Nobel Prize-winning author Orhan Pamuk was prosecuted for precisely this crime in 2005 although the Justice Ministry refused to let a trial proceed, following an embarrassing international outcry.

The accord has also upset Armenian nationalists – especially the powerful diaspora living in France, the US, Lebanon and elsewhere. They've staged large protests. Their position is that the only thing Turkey should do is admit guilt. They fear that the accord will undermine Armenia's diplomatic campaign to persuade countries around the world to officially recognise the events of 1915-19 as genocide.

What brought the two sides together?

In Turkey the policy of simply silencing debate about what happened to the Armenians is breaking down as more and more writers and intellectuals question the official line. The persistence of the dispute with Armenia is also damaging Turkey's hopes of joining the EU, partly because pro-Armenian sentiment is strong in some key states like France. In any case, the EU is unlikely to accept Turkey as a member while it has a "frozen conflict" with its eastern neighbour and while its frontier with Armenia remains shut.

What can Armenia get out of this?

A good deal, economically. Armenia is small, mountainous, infertile and landlocked. Blockaded by Turkey on one side and by Turkey's ally, Azerbaijan, on the other, its people have paid a high price for the dispute with Turkey. Poverty is widespread, the electricity supply is erratic, even in the capital, and many people have emigrated. Armenia has shown it can survive the Turkish blockade, thanks partly to the annual flow of remittances and other forms of aid that the wealthy diaspora sends back "home". But the country cannot flourish until relations with Turkey become are normalised. If relations really improved, Armenians might also be able to visit the many ruined Armenian churches and cathedrals in eastern Turkey, not to mention Mount Ararat, the symbol of Armenia, which also remains out of reach, just over the border.

What about the US in all this?

Hillary Clinton's presence in Switzerland at the weekend, urging the two sides to hurry up and sign the accord, was evidence of the importance that the US attaches to the dispute.

The US is in a dilemma over Armenia. As a senator, Barack Obama vocally supported the Armenian cause and pledged to publicly describe the events of 1915-19 as "genocide" if elected president. The main Armenian lobby groups in the US then urged their supporters to vote for Obama. Once in the White House, he started fudging the issue. Ideally Obama would like to square his earlier pro-Armenian commitments with the reality that Turkey is a far more important player than Armenia. If the two sides wind down the dispute themselves, of course, it helps Obama get out of a tight spot.

How does Azerbaijan come into the dispute?

This is where it gets complicated. The main reason why Turkey closed the border with Armenia is not because Armenians accuse Turks of genocide. It is because in 1993 Armenia invaded its own eastern neighbour, Azerbaijan, on behalf of the embattled and besieged Armenian enclave of Nagorny Karabakh, which had proclaimed independence from Azerbaijan.

The Turks, who see the Muslim Azerbaijanis as "kith and kin", were furious. The Armenians were equally furious, seeing Azerbaijan's attempt to crush the Armenian enclave militarily as a drive to "complete the Armenian genocide".

The question of whether the enclave's independence should be recognised, or whether it should become part of Armenia, or be returned to Azerbaijan's control, remains unresolved. It is yet another of the region's frozen disputes – much like the one between Georgia and Abkhazia. Azerbaijan officials meanwhile are disappointed by the accord. Their official standpoint has always been that Turkey must not reopen the border with Armenia until Armenia has agreed to the return of Nagorny Karabakh to Azerbaijan's rule.

Who cares about what Azerbaijan thinks?

Lots of people, in fact – not just their "Turkish brothers". Azerbaijan sits on one of the world's largest oil reserves in the Caspian Sea and as Europe is desperate to reduce its dependence on Russia as a supplier of energy, it has a strategic interest in Azerbaijan. The EU sees it as a crucial source of oil for the Nabucco pipeline. This is supposed to start transporting oil from Turkey to western Europe by about 2014, bypassing Russia.

So Russia has a stake?

Very much so, although the Kremlin's attitude to Armenia's disputes is somewhat sphinx-like. As an island of pro-Russian sentiment in the Caucasus, Armenia is important to Moscow and at times Russia enjoys posing as an older brother. It does not want Armenia to go the way of neighbouring Georgia and become a pro-American bastion. Russian public opinion also favours Christian Armenia over Muslim Azerbaijan – a factor of which the populist Kremlin leadership must take account. At the same time, the Kremlin doesn't want to alienate Azerbaijan, which was also part of the old USSR, or Turkey. It will encourage Armenia-Turkey rapprochement.

What happens next?

The signing of the accord is a milestone in the story of Armenian-Turkish relations but not the end of the story by any means. The two parliaments in Yerevan and Ankara must ratify the accord and a "yes" vote is not guaranteed in either assembly. As for the joint commission to examine what happened in the First World War, the question of who joins it and what it does will be enormously controversial. It may never get off the ground. But even if it doesn't, the reopening of the border between these two countries is an event of more than regional significance. Whatever reservations are felt on either side, the accord has to be good news.

Is the accord going to end decades of hatred?

Yes

*Whatever the Armenian diaspora says, growing numbers of people in Armenia want to trade and travel.

*Historians on both sides of the frontier are increasingly determined to query 'official' versions of history.

*Turkey knows it cannot advance its EU hopes while relations with its eastern neighbour are frozen.

No

*Nationalists in both countries are determined to prevent reconciliation and will lobby their two parliaments.

*Even if the two assemblies do ratify the agreement, it will do very little to undo decades of mutual animosity.

*By raising hopes that cannot be satisfied, the accord, paradoxically, may end up making matters worse.