I don't think his name is "Hassoun Wassef Ali", as there is noone by that name in the military name database. I've never not been able to find a service member's name there.
I think it is "wassef a hassoun" or "wassef hassoun". But Wassef A. Hassoun is listed as "not yet serving" and "considering joining." Strange.
Where did you find this military name database? Is it public?
The FNC is now reporting that the US military is confirming that a US marine is "missing" but will not confirm that it was a kidnapping.