Kill Assad?

In the Wall Street Journal, Bret Stephens argues that if President Obama attacks Syria, he should kill Bashar al-Assad.

Should President Obama decide to order a military strike against
Syria, his main order of business must be to kill Bashar Assad. Also,
Bashar's brother and principal henchman, Maher. Also, everyone else in
the Assad family with a claim on political power. Also, all of the