Was Islam Spread by the Sword?

I was reading a little Q&A at a Muslim apologetics site. The self-understanding of Islam is: yes, Islam was rightly spread in part by the sword. As the site says:

The fact that the sword and power were means of spreading Islam is not a sources of shame for Islam, rather it is one of its strengths and virtues... Islam spread by means of proof and evidence to those who listened to the message and responded to it, and it spread by means of force and the sword to those who were stubborn and arrogant, until they were overwhelmed and became no longer stubborn, and submitted to that reality.