Worst mistake in the islamic history?

The battle of Ankara 1402.

The Muslim Tamerlane's Army and Muslim Ottomans fought for nothing.

If this battle wouldnt have happened,Ottomans would have captured Constantinople almost 50 years earlier and Tamerlane would have invaded China.

Jagatai, no need to add words... Its the simplest answer.

This is the worst mistake in all our Turkish History also...

well that wouldn't hve happened if alkhawarj ( the first shias) who came from egypt assasinated Caliph Uthman.

azimuth they are not first shia and khwarij if you know khwarij appered after seffin and what is your problem with shia

dont forget uthman put a men from his family  in ranks they did not deseve it he was not a leader he was  ring in his family hand like Marwan bin alhakam ,ibn abi sarh,almughera bin shubaa he desroyed islam by his hand and made struglles inside our great religion

dont make me laugh by your post above firs shia it is fake 

The betrayel of Arabs against Ottoman Empire.

I thought again and I saw that the biggest fault of Muslims were not to realize the technological and wealthy developments in Europe after Renaissance and New World Discoveries.

The second one should be the Battle of Ankara.

The betrayel of Arabs in WWI was a great shame for them,but Ottomans would surely have been defeated in WWI even with the support of Arabs

Worst enemy of Muslims are Themselves

Their biggest mistakes were their own fault.

Ofcourse all Muslims are tought that if a Muslim and a Muslim are out to kill one another, both will go to hell.  (Because even the one who survived would have surely killed the other if he had the chance).

Theres a collective problem throughout the Islamic world.

Eastern Europeans (Muslim or otherwise) have a problem with Turks, Arabs have a problem with Turks,  Turks have a problem with Persians, Persians have a problem with Afghans, Afghans have a problem with Pakistanis, Pakistanis have problems with Indians.  Same goes in the CAR's, Uzbekistan hates Tajikistan, Tajikistan hates Qyrghizstan, etc.  All these nations have had problems with each other, and within their own societies.  Muslims have killed Muslims for as long as their has been Islam because the societies have been corrupted by greed, power, and ignorance.

From the time the imperialist nations knew there was a divide they could manipulate, they took full advantage of it.  Lots of despotic rulers in the Middle East are there today because of indirect or direct intervention by foreign powers.  Its the Muslim country's own fault, they put their own personal interests ahead of their own constituents.  Their hatred consumed them and thats what we have today.  An Islamic world that isn't based on Islam, but ethnocentrism, despotism, nepotism, and corruption.

The Islamic World (or lack there of) is ripe for the picking.

OK Azimuth but in your opinion you said he was a caliph and this his right but that is false he must choose the best for people islam said that if you dont mind brother.

About the fake caliph i want to know your opinion about him nd what is his idea when he fought his imam and the prince of the faithfulls.

notice yes i belive  he   he is not suppose to be caliph i guess you share me in the last idea.

well he "Muawyah" became Caliph and that is Fact wheather you accept it or not. so he was Caliph.

but anyway as far as i know Shiiti has different opinions about this so they have different set of Caliphs who didnt in Fact became Caliphs.

anyway what do i think about Muwayah fighting with Ali, i didnt do much reading about this  but as far as i know Muaweyah didnt want to accepet Ali as a Caliph if Ali didnt give him the people who assasinated Caliph Uthman.

since Muaweyah was a governor of syria he had an Authority over there and didnt join Caliph Ali. which made Caliph Ali as a Caliphate over Arabia and Iraq only i think.

i think it all went wrong and the name Caliph is not really represent what it actully meant at the begining.