Would transporting parts for a military radar instead of "missile parts" aboard a passenger aircraft make any difference under international law?

Question

According to Wikipedia:

On 10 October 2012, Turkish Air Force F-16s intercepted a Syrian Air Airbus A320, flight RB442 from Moscow to Damascus, in Turkish airspace and forced it to land at Esenboğa International Airport, suspecting it was carrying Russian-made weapons. Inspectors claimed confiscating ammunition, military communications equipment and items "thought to be missile parts", however evidence has not been publicly shown. The Russian foreign minister denied the claims and said that the plane cargo included only radar units.

However, the latter article (seemingly) from the Kommersant details that these were parts for a military radar on an integrated SAM system (Pantsir).

In mid-October, Russian Foreign Ministry spokesman Alexander Lukashevich reported that Turkey did not question the legitimacy of the cargo on board the plane en route from Moscow to Damascus. "It was an absolutely legal cargo - electrical equipment for the radar station," the diplomat explained. "Only the delivery scheme caused doubts." The fact that onboard the Airbus A320 there were 12 boxes with technical elements for the radar system of the air defense system, “Kommersant” reported immediately, as it became known about the interception of the aircraft (see “Kommersant” for October 12).

“But the delivery scheme turned out to be quite complicated,” the source admitted to Kommersant in the Russian government circles. “After the plane was detained in Ankara, it took us several days to figure it out.” According to him, the difficulty lay in the fact that subcontractors were involved in the delivery of radar elements of the Pantsir-S1 air defense systems manufactured in the KBP.

The decision to use the civilian side of the interlocutor "Kommersant" considers absolutely reasonable: first, the cargo did not pose a danger to the crew or the board, and secondly, information about the cargo would remain closed. However, these calculations were not justified: in the Turkish airspace the plane was intercepted. “The Turkish Air Force sent two F-16s to intercept, because they knew about the cargo being transported,” a source told Kommersant in the Russian government agencies. “They wouldn't risk that way without knowing about it for sure.”

According to "Kommersant", the FSB check on the fact of leakage of information about the shipment to Syria is almost complete. “With a great deal of confidence, we can say that the Russian departments are not involved in disclosing information,” a source in the Russian government says, “Most likely, this is the fault of the Syrian side.”

What difference does this make under international law, i.e. whether there were truly missile parts or just parts for the radar of a SAM system? (Turkey doesn't seem to have claimed they were explosives.) Under ICAO treaties etc., can one ship non-explosive parts for military systems via passenger aircraft overflying a 3rd country that might object to military equipment being flown over its territory, regardless of these objections?

Answer 1

There are so called "dual purpose goods": items that can be used both for civilian and military applications. These types of goods are heavily regulated. Dual purpose goods include, among numerous other components and even software, many types of radars of all kinds (search for "radar" in this EU document).

Dual purpose goods may have slightly different regulations but the import and export is often also highly regulated. For Netherlands, for instance, exporting military goods "generally requires a licence" and exporting dual purpose goods "often requires an export licence". This seems already subtle. If Turkey had the reasons to prevent transporting weapons on that shipment, same reasons likely applied for the dual purpose goods as well.