Azerbaijan’s relations with Iran, its large neighbor to the south, have been in flux since the end of last year’s war with Armenia.
The most recent rocky period started when Azerbaijan began charging Iranian trucks toll fees on a road heading for southern Armenia through slices of Azerbaijan’s territory, Eurasianet reported.
At first, Iran remained silent even after Azerbaijani police and customs confirmed the practice. Armenian media reported that some of the trucks targeted had been “transporting cement to Yerevan and Stepanakert”, the de facto capital of Nagorno-Karabakh.
The territory is internationally recognized as part of Azerbaijan but had been controlled by Armenian forces since the first war between the two sides in the 1990s.
The drivers were detained because they “entered Azerbaijan illegally from Armenia and relevant measures will be taken”, Spokesperson of Azerbaijan’s Ministry of Interior Affairs Ehsan Zahidov said the following day.
Azerbaijan has long held that entry into Karabakh via Armenia amounts to an illegal border crossing.
Iran’s Foreign Ministry responded by demanding the release of drivers and called for a meeting with Azerbaijani officials to resolve the issue.
A series of meetings have taken place since then, but the fate of the drivers is still unknown.
Iran’s Ambassador to Azerbaijan Abbas Mousavi met with Hikmet Hajiyev, the senior foreign policy adviser to Azerbaijan’s president, twice in a week.
In a tweet, Mousavi said the two “reviewed the current situation and the future of our good relations and other issues of interest”.
On Sept. 23, Azerbai, Hossein Amir-Abdollahian, on the sidelines of the United Nations General Assembly.
In a statement, the Azerbaijani MFA noted that the ministers reviewed the “current situation in the region”.
Tension has been exacerbated by naval military exercises conducted jointly by Turkey and Azerbaijan in the Caspian Sea. Iran’s Foreign Ministry said the drills violated an international convention banning foreign military forces from the sea.
Azerbaijani analysts retorted that Iran is the only Caspian littoral country not to have ratified the convention.
Iran then held its own military drills close to its border with Azerbaijan.
In Baku, analysts say the government appears to be motivated by long-running irritation at Iranian trucks supplying Nagorno-Karabakh.
Following Azerbaijan’s control over some stretches of the road, which connects the key southern Armenian cities of Goris and Kapan, and which is Armenia’s only highway linking Iran, Baku has been able to act on those Iranian deliveries.
The war also resulted in Azerbaijan regaining territory very close to the Lachin corridor, the road that connects Armenia to Nagorno-Karabakh. That has allowed Azerbaijan to control the road for what it sees as illegal border crossings.
Azerbaijan’s President Ilham Aliyev, in a Sept. 27 interview with Turkish media, said that between August 11 and Sept. 11, Baku had observed 60 Iranian trucks using the road.
He also said Iranian officials had repeatedly refused to act.
"The first time [the Azerbaijani side issued] a verbal warning, the second, an official note, and the third, posts – customs, border, police. In this way, we have begun to control the road through Azerbaijani territory," Aliyev said.
As a result, he said the number of Iranian trucks passing through Lachin has "dropped to zero".
While much of the Azerbaijani media coverage of the spat has emphasized a widespread belief that Iran is on Armenia’s side in the conflict, that is a misunderstanding, said political analyst, Eldar Mamedov.
Iran has “repeatedly supported Azerbaijan’s territorial integrity on the level of political and religious leadership”, Mamedov said.
As for the most recent tensions between the two countries, Mamedov suggests they will not fundamentally change the relationship.
“Iran is treading carefully in the Caucasus. It does not need destabilization of the northern border, in addition to all the challenges it already has in other scenarios like the Persian Gulf, Iraq and Afghanistan,” he said.