The commander of the Muslim army, which opened Andalusia for Islam, burnt his ships in the battle of "Wadi Birbat" or "Lukkah." He said to his army that was composed of 12 thousand soldiers, most of them were infantry while cavalrymen were few: "The sea is behind you and the enemy is in front of you; where do you think you will go?".
They claim he did that to force his soldiers to fight the enemy who were estimated of "100.000" cavalrymen. Thus the story was reported, but most trustworthy historians did not narrate that story although it was circulated at the hand of untrustworthy writers and thinkers.
Studying the story:
From the scientific aspect, this story is not valid, but rather cannot be certified because it lacks historic and scientific documentation, therefore, it is not valid.
Muslims were known for the science of "the chain of transmission" which was the reason for protecting and distinguishing authentic Hadiths from weak and fabricated narrations. They also established the science of "Invalidating Narrators," "Study of Narrators," and "causes" to verify the narrations of the Hadith, narrations of the Companions, sayings of Imams and scholars, and history and documentation.
If we subject that narration to scientific scrutiny, we find it lacking scientific standards; moreover investigation proves its weakness and that it was deliberately inserted into the history of Muslims. There is no mention of that story in the writings of the historians of Andalusia who lived during that period or the following historians of Andalusia, so there was no mention to such story and no one ever spoke about in their time. Therefore, they did not narrate it neither in their rumors nor in stories, no matter it was true or false.
However, those who spread it were not in the time of that incident but in modern times, mainly orientalists because of something in their hearts, then it was reported and disseminated by their followers. Then it was conveyed by people who do not know history or investigation, but those people were like a person who gathers news and stories from here and there without authentication and believed every story that was reported from the Europeans, believing in their infallibility, scientific method, and objectivity! Afterwards, it was conveyed to good people who lacked scientific investigation who accepted it with good intention and justified the story with nice interpretations.
From the military point of view: it is a big mistake, unsuitable adventure, and a risk in the enemy's land for some reasons:
1- It was not confirmed that the leader of the battle, Tariq ibn Ziyad, consulted his superior leader Musa Ibn Nusir because there were no correspondences neither at Muslims nor at the Europeans to prove that. If that happened, it would have been a military mistake which Tariq could not make.
2- The army might lose the battle, which is possible, because they were few in number and the differences between him and his enemy and because the land was not his, therefore loss might have taken place, where are you going to?
So, where to go and where is the chance for rearrangement if he was defeated but not destroyed? and how he would ask for reinforcement? By all strategic standards, that was a suicide mission. The leaders of the most powerful armies always put alternative plans for withdrawal or to protect themselves against total destruction.
3- Muslims do not need to such kind of (compulsion) to fight because it contains defamation to their intentions and turning sincerity and Jihad (fighting) that were intended for the sake of Allah into fight and escaping decisive death which indicate distortion in the Europeans' understandings about the belief of Muslims.
4- After burning the ships, how would be the returning way if the army has been defeated?
5- Most ships did not belong to Muslims but they were borrowed from the ruler of (Ceuta), so they were a trust that should be rendered to their owners.
6- One of researchers said: that claimed burning is unacceptable according to the Shari`ah and someone pious and god-fearing like Tariq Ibn Ziyad could not do such a thing and scholars and army emirs could not remain silent if that happened. Moreover, the narration contains belittling to the power and determination of the Muslim openers where they imagined that Muslims lost determination to fight, and escaping death was the only motive to fight which means: they were seeking worldly benefits.
That can be understood from the mentality of the European occupiers, therefore they suffered a lot when they faced the Mujahideen who have been seeking martyrdom. So, they searched history to fabricate that story which happened when the Persian invaded Yemen before Islam then attributed it to the leader of the Muslim army in Andalusia whom they claimed to force his army to fight, and if that was true, they would have run away and left him alone.
Did Tariq Ibn Ziyad burn his ships? - History - Thoughts and Knowledge - Alukah.net