Muslims Succumbing to Islam

Is it just me, or is “succumbing” an odd word to use in this instance? Reuters:

U.S. President Barack Obama vowed on Saturday that federal investigators would find out what motivated a married couple in California to shoot and kill 14 people, and he asked Americans to stand united after the attacks.

“We are strong. And we are resilient. And we will not be terrorized,” Obama said in his weekly address.

“It is entirely possible that these two attackers were radicalized to commit this act of terror,” Obama said. “And if so, it would underscore a threat we’ve been focused on for years – the danger of people succumbing to violent extremist ideologies.”

 
Did the “violent extremist ideology” sneek up on them first?