Economic involvement with Iran is one thing, but Serbia has a military security pact with Iran. That’s different.
“but Serbia has a military security pact with Iran.”
And your point is ???
Serbia has military/security pacts with several countries...including the US. The Serbian army even trains with Americans in Ohio (see: http://www.vojska.mod.gov.yu/eng/MVS/Ohajo/01.07.2007_bolja_komunikacija_sa_svetom.html)
Serbia also contributes to UN peacekeeping forces in Libera, Ivory Coast and DR Congo.