What is the main reason for the failure of the Arab peoples ?

In fact, while Islamic civilization seemed to be the most advanced or stable c 1000 CE, the arabs were never very innovative. They may have preserved ancient Greek knowledge but contributed little themselves, to astronomy or technology. Even medieval Europe was more advanced. Around the 13th century when windmills were going up all over Europe the chief Arab engineer said wind driven water was nonsense.

Now it IS true that the arabs had better military leadership in the past. Mohammed had good generals and allowed them to show initiative. In contrast, modern arab militaries have been plagued by serious pathologies causing disastrous failures on the battlefield, which have led to more general failure. According to Pollack, the most serious arab military problem of recent years has been lack of initiative on the part of officers. They didn't reorient their lines to meet a change in the direction of an enemy attack, and frequently lie to hide embarrassing truths.

At one time, many, many centuries ago, the Muslim World was churning out some of the most innovative technology and producing some of the most brilliant minds on this planet. Militarily they were quite adaptable and they were able to take the lessons that they'd learned in their defeats at the hands of the Chinese and turn them into viable tactics and techniques that led to victory after victory in their wars with Western countries. In astronomy, mathematics, explosives, and many other areas, they were quite advanced at one point. What happened was that the wide majority of them began to embrace a form of Islam which was not compatible with progress. This is still the source of the Muslim World's ills and failures today.

In the Muslim World, women are second-class citizens, Non-Muslims are not considered human beings, illiteracy and poverty are considered par for the course for the lower classes, blatant, brazen, open hatred and hostility for the members of other ethnic groups - whether they're Muslim or not is the norm. Shia and Sunni Muslims kill each other. Arab and Non-Arab Muslims kill each other. Islam is so permissible of hatred, hostility, violence and murder that Muslims cannot unite.

The most advanced countries which are primarily populated by Christians are those countries which are able to limit religion's place in their society. The Scandinavian countries and the Netherlands being prime examples. Just look at Latin America where everyone reports being Catholic. Not the most advanced countries in the New World, are they?

Failure at what time in history? In early medieval times Arab scholars kept the flame of science burning brightly when it had sunk to a dull ember in Christian Europe.

They went towards the wrong belief system of being komacosi thinking their is virgins in heaven to do insane things that aren't even moral to nature as an excuse to justify their actions.

The clever stuff from that culture was done by slaves, christians, Jesws and recent converts.

A religion of compression and conformity produces a people of conformity.

Define failure.

Just became they do not live up to your standards does not make them failures.

Wearing sandals and a toga

Hate for their fellow man. Seems to me they hold grudges and hate on their own because of petty things like religion and geography.

Cultural conditioning has led you to your observation. Does that make it valid? No.