On September 19, Azerbaijan launched a massive assault on the Armenian-populated Nagorno-Karabakh region. It appears intent on establishing full control over the territory. 

The population of Nagorno-Karabakh - which has been under siege for the past nine months, enduring acute food and supply shortages - is left to its own devices to resist despite the presence of Russian peacekeepers stationed there since the last full-scale war in 2020. 

Armenia is staying out of it, wary of the risk of further Azerbaijani incursions into its own territory. The EU and Russia  are calling on both sides to stop fighting, and Turkey is "standing by Azerbaijan as always."

The offensive was presaged by Azerbaijani troop and hardware movements and supplies of weapons from Israel. It started at about 1 pm local time, when the Azerbaijani Defense Ministry announced the launch of "local anti-terrorist operations aimed at restoring constitutional order" in Karabakh. It was cast as a response to alleged Armenian militarization and mining activities amid the deaths of two employees of the Azerbaijan Motor Roads State Agency and four policemen in separate mine blasts in different areas around Nagorno-Karabakh early that morning. 

The ministry vowed to only attack military targets and said it urged Armenian civilians - through SMS, loudspeakers and leaflets - to stay away from military facilities.

It added that humanitarian corridors had been set up for civilians in order to "ensure the evacuation of the population from the danger zone," including on the Lachin road, which connects Nagorno-Karabakh to Armenia and the outside world. 

It said that it had informed the Russian peacekeeping contingent in Nagorno-Karabakh about the operation prior to launching it. 

In the ensuing hours Azerbaijani media outlets and social media users circulated Defense Ministry videos purporting to show explosions of military installations belonging to the "Armenian armed forces." (The phrasing is a pointed refusal to differentiate between Armenian and Karabakhi armed forces.)

Meanwhile, images came out of Nagorno-Karabakh showing damage to apartment blocks and other civilian infrastructure. Towards evening a former official wrote that 26 civilians, including 11 children, had been wounded and two civilians, one of them a child, had been killed.

Azerbaijan also reported a civilian killed in Shusha, apparently as a result of fire from the Karabakhi Armenian forces. 

In a post on X (formerly Twitter) about four hours after the assault began, Azerbaijani presidential advisor for foreign affairs Hikmet Hajiyev reiterated Baku's longstanding demand that the "illegal separatist puppet regime" (the de facto government of Nagorno-Karabakh) dissolve itself and that all units of "armenian armed forces" there be disarmed. 

A short time later, Hajiyev told Turkish television that most military targets in Nagorno-Karabakh had been neutralized and that now smaller, surgical operations were underway.

At about 7 pm local time, the Azerbaijani presidential administration said it was ready to meet with "representatives of the Armenian residents" of the region in Yevlakh, a nearby Azerbaijani town (which Baku had previously suggested as a talks venue). 

"However, in order to stop the anti-terrorist measures, the illegal Armenian armed groups must raise the white flag, hand over all weapons, and the illegal regime must disband themselves. Otherwise, anti-terrorist measures will be continued until the end," the administration said.

Armenian Prime Minister Nikol Pashinyan's first public reaction to the fighting was to reject any notion that the Republic of Armenia was involved or planned to intervene. He reiterated that Armenia has no troops there. 

(Armenia's and Nagorno-Karabakh's armed forces had been largely integrated for years but that changed after the Second Karabakh War in 2020.)

In the evening Pashinyan spoke to U.S. Secretary of State Antony Blinken and French President Emmanuel Macron about the situation.