The largest paramilitary operations ever undertaken by the CIA took place in the small Southeast Asian Kingdom of Laos….Air America, an airline secretly owned by the CIA, was a vital component in the Agency's operations in Laos. By the summer of 1970, the airline had some two dozen twin-engine transports, another two dozen short-takeoff-and-landing (STOL) aircraft, and some 30 helicopters dedicated to operations in Laos.

Above is taken from the CIA's website, it describes Air America’s “clandestine” operations, destined to spectacular failure, by the CIA during the bloody Laos war.
An investigative report by Rueters in the use of civilian planes to ferry soldiers, mercenaries and materials of war to Syria to sustain the murderous Assad regime in part says:

In recent years, dozens of planes have been registered in Ukraine to two firms, Khors and Dart, that were founded by a former Soviet marine major and his onetime military comrades, according to the Ukraine national aircraft register. The planes were then sold or leased and ended up being operated by Iranian and Syrian airlines, according to the flight-tracking data.

In a corner of the departures area at Rostov airport in southern Russia, a group of about 130 men, many of them carrying overstuffed military-style rucksacks, lined up at four check-in desks beneath screens that showed no flight number or destination.

The operation lays bare the gaps in the U.S. sanctions, which are designed to starve Assad and his allies in Iran’s Revolutionary Guard and the Hezbollah militia of the men and materiel they need to wage their military campaign.”

In other words; in copycatting clandestine CIA Air America operation, the unreformable, expansionist and warmongering Islamist fascists are using Iranian airlines which utilize American and European civilian planes.

Airtight sanctions, a la against the despicable South Africa apartheid, works. U.S. lawmakers get to it.

Picture above; Islamist fascists’ Quds force members being flown to Syria aboard an Iran Air plane.