The arrest sets a chilling precedent, as most of the adult male population of the region has either fought against Azerbaijan or served in the local army, which Baku calls an "illegal armed formation."
Azerbaijan seems happy with the EU-mediated track of negotiations with Armenia while seeing Russia as a barrier on the path to integrating Nagorno-Karabakh.
Azerbaijan shut down all traffic between Nagorno-Karabakh and the outside world on June 15, exacerbating shortages and preventing patients from seeking urgent medical care.
Azerbaijan, which had been pressing hard for a resolution, has eased off following the Turkish elections and their establishment of a border post in Karabakh.
His outspoken criticism of Iran, and the timing coinciding with the opening of Azerbaijan's embassy in Israel led some fellow MPs to point the finger at Tehran.