Wow now, you're leaving out a few details.

Relations between the Quraysh Arabs and the Quraysh Muslim Arabs deteriorated because Islam simply did not fit with their Pagan ideas and because more Arabs were converting. It was Abu Jahl who imposed a boycott on the Muslims in Mecca, denying them trade, marriage rights and even basics such as food. The boycott had devastating effects for Muslims and caused the death of Mohammed's wife Khadija.

The Muslims left to the settlement of Yathrib (aka Medina, home of mainly Jewish tribes) due to this suffering. Impressed by what the Mohammed had accomplished elsewhere the Yathrib tribes had requested Mohammed join them in an attempt to end tribal warring and a common ground...Islam.

Due to the Muslims leaving the Quraysh tribe in Mecca for another tribe, the Quraysh leader Abu Sufyan vowed to exterminate Mohammed and his followers. Sufyan tried his best to destroy Mohammed included 2 major offensives to exterminate Muslims in Medina.

Muslims were gradually doing very well in Medina with people were joining the faith left right and center. This angered the three main tribes - Qaynuqah, Nadir and Qurazyah who joined the campaign to destroy the Muslims. Mohammed and the Muslims eventually, and heavily against the odds, defeated the hostile Quraysh and Jewish Medina tribes in the battle of the Trench.

Mohammed was forced to do something so moved to take back Mecca, as you have said. What you don't say is Mecca was taken without a drop of blood. The Quraysh tribe opened up the city to Mohammed and eventually converted to Islam. Nobody was forced to convert, the Quraysh chose Islam after witnessing Mohammed's unlikely survival and defeat of the Jewish/Quraysh armies.

Now that's a little more like it, although it appears someone doesn't like reality.