[2][1] Orlov's extensive work: Review of the South-West Theatre of War (Russian: Обзор юго-западного театра войны), compiled in 1886–7, was kept in manuscript in the Military-Scientific Committee.

In his dissertation Orlov held a completely new view of Alexander Suvorov's actions in Italy and especially the battle of Novi.

In compiling this work, Orlov used the works of such historians/writers as Dmitry Milyutin, Alexander Petrushevsky, Yegor Fuchs [ru], Wilhelm Rüstow, Nikolay Gryazev [ru], Carl von Clausewitz, and Antoine-Henri Jomini; Orlov brought French and Austrian sources, never translated into Russian, as well as numerous detailed maps illustrating the fighting course.

From Boduna Orlov advanced General Rennenkampf to Jilin, where he also moved with the Hailar Detachment, but, by order of his superiors, was forced to turn to Harbin.

Upon arrival to the Manchurian Army Orlov participated in the combats near Liaoyang, on the left flank, at the Yantai Mines.

Here on 2 September he took part in a hand-to-hand infantry fight, being on horseback the whole time, and was wounded from 20 paces in the stomach by two bullets and concussed by two more.

In the battle of Mukden Orlov commanded the rearguard of the XVII Army Corps and on 10 March endured a day of hard fighting in 3 consecutive positions.

During the Mukden combats Orlov's division suffered a loss of 5,700 people, and he himself was shell-shocked in the head, but he did not leave the command and continued to be the chief of the rearguard until the army stopped at the Sipingjie positions: then he was appointed chief of the 3rd Army's advance guard and commanded it until the peace was ratified.

[1][3] Having switched from professorship to military service, Orlov published: Zabaikals in Manchuria – sketch of the campaign of the Hailar Detachment (Russian: Забайкальцы в Манчжурии — очерк похода Хайларского отряда); The Battle of Grunwald in 1410 (Russian: Сражение при Грюнвальде в 1410 г.