Russia has ensured that it will honor a deal providing Iran with the S-300 sophisticated anti-aircraft system, Tehran's envoy to Moscow says....the Russian side has cited technical problems which it said it was working on to fix....neither Iran nor Russia planned to "go back" on the contract, which he said was "profitable" for both sides. Iran has been trying to obtain the sophisticated defense system to improve its deterrence power in reaction to Israeli war rhetoric. According to Western experts, the S-300 missile defense system would shield Iranian nuclear sites against any Israeli airstrike. The S-300 system, which can track targets and fire at aircraft 120 km (75 miles) away, features high jamming immunity and is able to simultaneously engage up to 100 targets.