I was confused by this two terms, "作战半径" and "range",

respectively.  I thought that "range" refers to the maximum distance an aircraft can go one way.  If an aircraft flies beyond its range, it risks not having enough fuel when it heads back to air base. 

To my knowledge, how long an aircraft can stay on air depends upon the amount of fuel it can carry.  Take the German fighter Bf-109E during Battle of Britain as an example.  It had a roughly 660km range.  The fuel it carried could only support the aircraft to fight on England airspace for 20 minutes or so. 

A radius of 700km (with the presence of an Extender) is kinda low compared to the range of the Russian Su-33, which has 3,000km.  No?