The Nagorno-Karabakh conflict is more or less well-known and quite old and has gone through many phases. Armenia won the 1994 war with Azerbaijan and occupied 7 of its provinces plus Nagorno-Karabakh. This was natural as Armenia has always had much better armaments because it was more supported by the Russian leadership. The religious dimension of the conflict should also not be overlooked as the Armenians fought against the "Turkish" Azeri Muslims to avenge the Turks. From then until three months ago, there were occasional tensions between the two countries but nothing more. Much has been written about the reasons for the recent escalation of the conflict between the two countries.
So why now?
The regime in Azerbaijan continues to be dictatorial. Like Syria. Power passed from father to son. Nevertheless, Aliyev the son realized that something needs to change. In this context, he realized that he can no longer rely only on Russia but must create new alliances. Thus, he began to communicate with Turkey and the EU. Unfortunately, France blocked this approach because it wanted that the EU supports Armenia (photo 1).
Photo 1. French vision for the Armenian territories (Photo from Twitter @laurentwauquiez)
Israel also responded to Azerbaijan's efforts to reach out to other countries, as the former's proximity to Iran offers the latter the ability to monitor it. Thus, Azerbaijan was one of the first countries to recognize the state of Israel. It goes without saying that Israel supplied Azerbaijan with weapons and drones, so gradually its military machine became stronger.
In this period of American time-out until the presidential elections, Azerbaijan knows that the US not stop it from a war that seeks to create a strong card in the field that will use it at the negotiating table. This, of course, with the help of Turkey, which, in the midst of time-out, is counting on successes in Libya, where it intervened quickly and vigorously, changing the military balance on the ground and gaining a strong foothold at the forthcoming solution to the Libyan crisis. It is now using the same tactics in Azerbaijan, something that is evident in the field. Operationally, this is the tactic used by Turkey in Operation "Olive Branch" in Afrin, Syria, which has a similar soil morphology to Nagorno Karabakh (photos 2 & 3) and apparently pays off.
Photo 2. Azeri gains on the 4th of Oct. 2020
Photo 3. Afrin - Operation Olive Branch
One month before the start of hostilities, Azerbaijan received intelligence that Armenia was going to strike the gas pipeline to Turkey and Europe at the suggestion of Russia. This gave the players of this conflict the opportunity to move on.
Turkey knows that Russia needs it in Libya, so it will not argue with it on the issue of Nagorno Karabakh. On the other hand, Armenia did not expect such fierce resistance from Azerbaijan.
Azeri progress in the field led to Putin's recent statement that Russia should not support Armenia (under the CSTO) clarifying its stance on the conflict https://www.themoscowtimes.com/2020/10/07/russias-security-guarantees-for-armenia-dont-extend-to-karabakh-putin-says-a71687
Similarly, Ali Akbar Velayati's statement - I remind that Iran continues to support Armenia by supplying weapons and sending fighters of the Hezbollah and IRGC militias - according to which "Armenia must withdraw from the occupied territories of Azerbaijan."
As the war continues, the chances of Armenia losing even more territory increase. The forthcoming Lavrov-Pashinyan meeting will obviously have this purpose: for Armenia to accept a political solution and withdraw completely from Nagorno-Karabakh and the 7 provinces it occupied. If this does not happen and the hostilities continue, Azerbaijan's victory is the most probable, so Armenia will be dragged to the negotiating table after many losses.
Turkey's gains from this victory are: a) it will have free Azeri gas for at least the next 10 years, b) it proves the high quality of the Turkish defence industry, especially drones, and c) it appears to be credible and actively supports its friends and allies, unlike Russia. This will bring the other CSTO countries into its arms.
From the above, it is clear that Russia is retreating significantly, something that was expected from the previous experience in Syria where it came after the green light of the US and has shown an inability to deal with regular Israeli airstrikes mainly at the political level. In addition, the S400 have not met their expectations in either Syria or Armenia, and the crises in Belarus and Kyrgyzstan are deterrents to a new Russian intervention.