First of all, it should be noted that this work is a collection of essays by individual experts. Therefore, each chapter has a rather independent character, does not continue or supplement the previous and following chapters. Based on their areas of specialization, the experts focus on various aspects of the conduct and results of the Second Karabakh War. It does not make sense to analyze each thought of the experts separately (the work is not so huge), so I will try to briefly express my opinion about what I think about their analyses as a whole, but taking into account the specifics of the analysis of each individual expert.

Why did the war come as a surprise to many, in particular to the Armenians? 

In my opinion, Alexander Iskandaryan asked and answered this question best of all. According to his analysis, two conclusions can be drawn: first, Armenian experts are divided according to their areas of specialization. So, experts on the post-Soviet space do not overlap with researchers of the Middle East. This situation led to the fact that the possible role of Turkey in this conflict was ignored or was not evaluated objectively. The fact is that Turkey is considered primarily a Middle Eastern state, and the possibilities of its geopolitical maneuverability in the South Caucasus are strictly limited by the most influential player in the region – Russia. This underestimation made Armenian experts think that Turkey would not dare to help Azerbaijan, fearing clashes with Russia, and Azerbaijan, left alone, would not dare to launch a large-scale war. Here it is impossible not to emphasize Mr. Iskandaryan's “obsession” with the role of Turkey, which is described as decisive. The role of Turkey, of course, is one of the most important, but the hyperbole is certainly felt. 

Secondly, Mr. Iskandaryan claims that as a result of the generation change in Armenia, the current youth began to think more about integration into Europe than about Karabakh. The government of Nikol Pashinyan is an expression of the ideas of young people who willingly want to establish democratic principles as the main ones in the Armenian statehood. Therefore, the topics of Karabakh and the war dropped out of the priorities of the Armenian government, since the majority in Armenia were confident that the democratic government would be able to come to a common denominator with Azerbaijan and conclude a permanent peace. At the same time, of course, Azerbaijan's purchases of modern weapons, reforming its army, conducting dozens of military exercises with Turkey and other similar cases were ignored. According to Mr. Iskandaryan, it was these cases that led to the results that we have today. It should be noted that his arguments are objective and give a good explanation of the effect of the suddenness of the Second Karabakh War.

Why did Azerbaijan win the war?

The study describes in detail the course of events of the war and provides an analysis of its political and military aspects. D. Barry and L. A. Nersisyan contributed to the military-technical aspect. If Mr. Barry wrote only a purely technical aspect, comparing the arsenal of weapons that Azerbaijan and Armenia had, then Mr. Nersisyan dwelled in more detail on the use, paying special attention to the strategic and tactical advantage of the parties. At the end of his analysis, Barry comes to the conclusion that Azerbaijan won thanks to the much better equipment of its army with modern weapons, such as attack UAVs purchased from its closest ally Turkey and kamikaze drones purchased from Israel. According to the expert, these military means helped Azerbaijan to win not because they are technologically unique and have no alternatives on the battlefield, but because there was nothing in the arsenal of the Armenian Armed Forces that could be opposed to Azerbaijani drones. The Armenian Armed Forces did not have strike UAVs, and their effectiveness was not high. L. A. Nersisyan, who also emphasized the military-technological advantage of Azerbaijan, also drew attention to Armenia's unpreparedness for war and Azerbaijan's successful military strategy. The expert claims that the mobilization and the order for full combat readiness of the Armenian troops were organized untimely and unsuccessfully, which gave Azerbaijan a strong advantage in time. Even at the very beginning of the hostilities, a significant amount of air defense and artillery of the unrecognized Karabakh were destroyed, which left little prospect for military maneuvers and demoralized the Armenians. Of course, reading the analyses of both military experts, it is impossible not to notice a more comprehensive analysis of Mr. Nersisyan. Since Mr. Nersisyan discusses not only the military-technical advantage of the Azerbaijani Armed Forces, but also describes their skillful and effective use.

The study also discusses the political forces of the parties represented by their allies. Expert Kerim Khas claims that Azerbaijan had more political resources than Armenia. First, Azerbaijan was actively supported by Turkey, a NATO country, while Armenia, whose main ally is the Russian Federation, could not receive such unequivocal support. Moreover, Kerim Khas is sure that for Great Britain, which invested in Azerbaijan through the British Petroleum (BP) oil company and is a close ally of Turkey in contrast to other European powers, the victory of Azerbaijan and the growing influence of Turkey's role in the region were definitely preferable to the victory of Armenia. Moreover, despite the differences with Turkey, the United States was also interested in Turkey taking a more active role in the South Caucasus, thereby balancing Russia. It is interesting that the authors somehow forgot to mention Pakistan's political support for Azerbaijan.

According to Mr. Khas, Armenia had two potential allies: Russia and France. However, Russia preferred to adhere to a neutral position, in view of its relations with Azerbaijan and the unfavorable government pressure in Azerbaijan. And France, despite the almost unequivocal support in favor of Armenia, is not directly interested in getting involved in the conflict in the South Caucasus. As a result, Armenia lacked significant support from other states. 

In general, we can agree with Mr. Khas, although it is necessary to take into account the sending of Russian weapons to Armenia through Iranian territory, which partly changes the picture of "Armenia left without support."

Who got the geopolitical triumph after the war and what will happen next?

The fact that Azerbaijan won cannot cause any doubts, but an ambiguous answer should be given to the above question, reflecting a wide range of realities. K. V. Makienko and R. N. Pukhov are sure that the arguments about the Russian geopolitical victory are problematic, since, first of all, this is due to the temporary restriction – a five–year period of the stay of Russian peacekeepers in the liberated territories of Karabakh. The experts noted that the previous status quo was preferable to Russia, which gave it more opportunities as a lever of pressure on Azerbaijan and Armenia. Moreover, Makiyenko and Pukhov quite speak about the role of the CSTO, which, in their opinion, should have intervened in the conflict on the side of Armenia. Despite the fact that the statements of the Russian leadership about the lack of obligations of the CSTO to fight outside the internationally recognized borders of Armenia were legally sound, such behavior will inevitably create ideas about the ineffective functioning of the CSTO among its other member countries and strengthen the image of Turkey among the post-Soviet countries. Therefore, Makiyenko and Pukhov suggest that the Second Karabakh War is a loss for Russia and a victory for Turkey, which has strengthened its influence and presence in the South Caucasus.

Dimitri Trenin also confirms that the results of the war were unfavorable for Russia and claims that the deployment of Russian peacekeeping forces is not a stable lever of pressure on the region. Mr. Trenin also believes that Russia had to recognize Turkey as a player in the South Caucasus, which makes balancing Turkey in other regions of contact, for example in Syria, an imperative of Russian foreign policy. At the very end, d. Trenin notes that if there is a new war in Karabakh, Russia will no longer be able to maintain a neutral position and the consequences may be more unfavorable for it. 

Notes

Based on the above-described analyses, it can be concluded that the Second Karabakh War made relations between the countries of the region more complex. Russia has lost its influence to some extent, and Turkey has strengthened it. 
According to most experts, Azerbaijan's advantage in the air played a role in the military victory. 

I did not comment on Mr. Derlugyan's analysis specifically, as I see a lack of analytical objectivity in it.