Born in Relizane, Algeria, Smaïl moved to France at a young age and began competing for his adopted country in 2006, taking part in the 2006 European Cross Country Championships (finishing 11th in the junior race), and the 2006 World Junior Championships in Athletics (reaching the 5000 m final). The 2007 season saw significant improvement as he took the 5000 m gold at the 2007 European Athletics U23 Championships. His progress stalled however in the following year, as he only managed 64th place in the U23 section of the 2008 European Cross Country Championships.