Religion is a system of beliefs. You can convert to a religion. What you cannot do is convert to an action. You cannot convert to “terrorism” as much as I could convert to “jumping.”
But this is the pathological nature of Islam- Muslims, especially pious ones, will say and do anything to “defend” Islam and will never address the fact that the problem is Islam itself. First they called it the religion of peace, then they called terrorism “extremism,” then “radicalism,” then “violent extremism,” and now in apparently a new low, somebody is now calling it “converting to terrorism.”
As the presenter of this clip notes, the common denominator between all of the violence in Europe and the terrorist attacks is Islam, because Islam is the problem.