At the beginning of the Russo-Japanese war, Yudenich commanded the 18th regiment of infantry (5th infantry brigade) and stands on several occasions. During the battle of Sandepu, he personally led troops who begin to retreat to engage in a fight to the bayonet and manages to repel the enemy. In the battle of Mukden, he also led the attack and actively manages its perimeter defense. He was seriously wounded and received the sword of Saint George with the inscription "for bravery". At the request of the allies, the Caucasus army began an offensive on two axes – Baghdad and Penjwin – early February 1917. The operation is proceeding successfully. The 1st corps of the Caucasus of Kalitine arrives at the border of Mesopotamia, as the 7th corps of the Caucasus Vadbolski-controlled approaches of Penjwin. This offensive provides considerable assistance to British troops by forcing the ottoman command to project a part of his troops to the Russian Front, which weakens the defense of Baghdad. The British are thus able to go on the offensive and take Baghdad. The 6th Turkish army retreated to the North and ends up taking vise, risking defeat. After the Revolution of February, early March 1917, Yudenich was appointed commander of the Caucasus Front. In this period the chaos begins to spread in Russia and this region. The agitation gained units and discipline fall. In assessing the situation in all aspects, Yudenich decided to stop the campaign of Mesopotamia and withdraw troops from the montane regions with better parking conditions to move to the defensive. The 1st and 7th corps of the Caucasus are receding. The general refused to obey the order of the provisional Government to relaunch the offensive required by the allies and provides a substantial report on the actual situation on the Caucasus Front and the State of the troops at Stavka. In May 1917, the provisional Government dismisses Yudenich’s command on the front for disobedience. .