Mohamed Ben Madani, editor of the London-based journal Maghreb Review, analyses Mauritania's power struggles for the BBC News website following the latest coup:
Does the coup come as a surprise?
No, there is a lot of opposition in the country to President Maaouiya Ould Sid Ahmed Taya's close relations with Israel and the United States.
Overthrown President Taya has arrived in Niger
Most Mauritanians believe that the US has double standards when it comes to dealing with the Israeli-Palestinian conflict.
This is the fourth attempted coup d'etat within two years. The most serious one took place in June 2003, when more than 150 people died and a lot of military equipment was destroyed in the battles. There were two others in 2004, one in August and the second one in September. They have just finished trying the officers of those two coup attempts.
Mauritania is only the third Arab country to recognise Israel - Egypt and Jordan being the other two.
Who is behind these coup attempts?
They are led by the military establishment but their support comes from Islamist movements within the popular opposition. Earlier this year the opposition made it clear they would support any toppling of President Taya which led to democratic elections.
But if this coup succeeds, the leaders will find it difficult to find legitimacy, as African countries have agreed that they will not recognise those who lead military coups.
Why has President Taya taken refuge in Niger?
Niger's President Mamadou Tanja is a very close friend of his. He recently intervened to sort out Mauritania's frosty relations with Algeria and Libya.
At an Arab League meeting in March, Algeria and Libya tried to get Mauritania to withdraw its support for Israel. But Mauritania refused and Libya's ambassador has still not returned to Nouakchott.
Burkina Faso, which has been accused of being behind the coup attempts in 2004, is also a close ally of Libya and is a beneficiary of Libyan aid.
How close are Mauritania's relations with the US and Israel?
For the past four years, the US has used Mauritania as a base to gather intelligence on Islamists in Sub-Saharan Africa, which has upset Mauritania's neighbours.
The Americans have failed the Mauritanian regime. They have had consultants in Mauritania since last June to advise on Islamic terrorists and also to improve armed forces intelligence.
This unit of 150 men is still in Nouakchott and failed to notice any change of behaviour in the National Guard.
The Israelis also have secret service agents in Mauritania. Israel is keen to foster close relations as it wants Arab recognition and Mauritania's newly discovered oil.
Oil exports to Israel are due to start in January next year.
In return, the Israelis have given substantial aid to Mauritania but a large Israeli-built hospital in Nouakchott is boycotted by most Mauritanians on principle.
Is Mauritania particularly religious?
It is a very conservative Sunni Muslim country. However, I would not say it is fundamentalist.
But there is a feeling that US President George Bush is leading a crusade against Islam.
Will the Israeli embassy in Mauritania be closed?
I am quite sure it will be closed within the next three weeks.