False equivalencies are always bad and irrational. Firstly ...the Jews of WW2 bear zero comparison to Sunni Muslims leaving Syria. Namely because..no one is summarily executing Sunni Muslims. ISIS is not. The rebels fighting the regime are not. The government of Syria is not.
Further...why in blazes is anyone bringing up Japanese internment? Literally no one anywhere is suggesting at all that we lock up all Muslims Americans. Speaking of an irrational fear.... As far as simply banning people from certain countries from entry, we have a clear history of doing exactly that. During WW2 immigration from Germany, Italy and Japan was stopped. In 1979 the United States ceased immigration from Iran.
Finally...our policy should not be based in anyway on whether or not we think our enemy wants us to do something or not. That is just flawed thinking. We should derive policy from thoughts on what is good for this country and no other consideration. What is absolutely common sense right now is to validate as well as humanly possible the background of anyone entering the country regardless of the entry point. That is good policy. That is consistent with our values. It is smart policy.
Oh and...to the idea that American Muslims do not speak up out of fear....true...but the fear is of...their radical friends, neighbors and brethren. That is not a good argument for being an open target as a nation.