Iranian President Hassan Rouhani is calling for “stability” and an “end” to the current fighting between Armenia and Azerbaijan — but should the conflict between its northern neighbors escalate, Tehran may well deepen its involvement.

What to watch: Iran's recent history — specifically the Iran-Iraq War (1980-1988) — provides a model of how that escalation might happen.

The big picture: The foreign-supplied arsenals boasted by both Armenia and Azerbaijan carry the risk of missile salvos targeting one another’s population centers, as seen in the "War of the Cities" between Iran and Iraq.

Another similarity between the two conflicts is the role of proxy forces.

• Iran created Lebanese Hezbollah in 1982, the same year it invaded Iraq. During the war, Tehran relied on the Badr Organization, a group of Iraqi Shiite exiles to fight Saddam Hussein’s army.
• Now, there are reportedly Syrian jihadists fighting on Azerbaijan’s side, with support from Turkey, a development Iran’s Rouhani called “unacceptable.”

The Iran-Iraq War also demonstrates that new alliances can come together, and multiple conflicts can converge, over the course of a larger war.

• For example, Iran unsuccessfully took on the U.S. Navy in the Persian Gulf during its war with Iraq.
• Where things stand: Turkey is already playing an active role in the conflict in Nagorno-Karabakh and another neighbor, Russia, clearly has interests to protect as well.

What to watch: Less attention is being played to the role of a third neighbor, Iran, which previously backed Christian Armenia rather than Shiite Azerbaijan when the two went to war in the 1990s, a decision best explained by geopolitics.

• Tehran officially supports Azerbaijan's territorial integrity (Nagorno-Karabakh is inside Azerbaijan's borders), but has been accused of favoring Armenia and providing supplies to the Armenian-aligned government in Nagorno-Karabakh prior to the recent flare-up (Iran denies that).
• There have been at least two indications that Iran may take a larger role now: ethnic Azeri protests in Iran in favor of Azerbaijan, and warnings by Iranian security officials that a spillover of shelling into Iranian territory won't be tolerated.
• Iran may also seize any opportunities to export weapons and offset adversaries like Israel, which is a leading arms exporter to Azerbaijan.

The bottom line: If the peaceful settlement Rouhani and others are calling for arrives soon, those calculations won't come into play. If not, we could see shadows of another war that began four decades ago.

Behnam Ben Taleblu is a senior fellow at the Foundation for Defense of Democracies