At the beginning of the First World War, Ivanov was appointed commander-in-chief of the Southwestern Front.
At first, he together with the aged general von Saltza suffered a minor defeat at Kraśnik, but success came next when the Russians successfully advanced into Austrian Galicia, with the Russian casualties of about 200,000, the Austrians having roughly twice the casualties, including thousands of POWs.
For the huge successes at the front, he was awarded the Order of St. Vladimir, 1st class with swords, and the Order of St, George of the 2nd degree, being three of the only generals that were awarded this high decoration, the other two generals being General Nikolai Ruzsky and Nikolai Yudenich.
During the battle at the Vistula River, he with his Southwestern Front armies (4th Army and the 9th Army), together with the Northwestern Front commander-in-chief General Ruzsky with his armies (2nd Army and the 5th Army) from the North.
In the matter of a month, General Ivanov and General Ruzsky's troops successfully repulsed the German advance, taking about a hundred kilometres of land.
Later on, General Ivanov commanded an operation towards Kraków, it was successful at first, but was later ordered to retreat, ending the initial success.

In early 1915, General Ivanov gained approval of the Stavka to launch an offensive towards Hungary, but the offensive was disturbed by the Germans in Poland.
Furthermore, the Austro-German forces launched an offensive in southern Poland.
During the battle, the Russians suffered casualties up to 350 thousand men, and the Russians were pushed out of Galicia, starting the Russian Great Retreat.
General Ivanov repeatedly showed examples of poor leadership of the troops and indecisiveness, much like many other Russian generals at that time.
Most particularly, he and the General Radko Dimitriev (commander of the 3rd Army) didn't make any effort to strengthen the 3rd Army, which the Austro-German forces inflicted the main blow at and nearly wiping the army.

Later in June, General Ivanov ordered General Nikolai Khodorovich, commander-in-chief of the Kiev Military District, to take 1 in a 1000 local German civilians as hostages, and imprison them for the rest of the war.
General Ivanov also prescribed to requisition that all the German hostages could only have a small portion of food of all the supplies they had got, and the hostages were settled in a highly secured residence.
And if any hostages didn't follow the orders, they would be met with death penalty.

Later at the end of 1915, he conducted a failed operation by the 11th Army against the enemy's forces.
And in March 1916, he was replaced by General Aleksei Brusilov as the commander-in-chief of the Southwestern Front, he was then appointed a member of the State Council, and was made adjutant to tsar Nicholas II himself.
General Brusilov recalled that, when he arrived and accepted the post, General Ivanov burst into tears and said that he couldn't understand why he was to be replaced.
General Brusilov assumed that it was due to the fact that General Ivanov was too passive, who believed that the front couldn't succeed.

General Ivanov, with his loyalty towards the tsar and surprisingly the tsarina Alexandra Feodorovna and the mystic Rasputin as well, he enjoyed great confidence and reputation from the royal family.
After General Mikhail Alekseyev was appointed chief of staff to the supreme commander-in-chief in mid 1915, which was the tsar himself, the tsarina wrote a letter to her husband, advising him not to let Alekseyev the only person in charge of the Stavka and advised him to let Ivanov to assist him, saying that:
You will be more relaxed, and Alekseyev will not bear one responsibility.

Further actions showed that it was Ivanov was the mastermind behind Alekseyev, who was not trusted by the tsarina.
In return, Ivanov was treated very well by Nicholas.
Later on, the tsar wrote to his wife:
I am very glad to see old Ivanov.
Fortunately, he grumbled less than ordinary.
He asked you to send him your new photo; please do it - it will calm the glori
At the beginning of the First World War, Ivanov was appointed commander-in-chief of the Southwestern Front. At first, he together with the aged general von Saltza suffered a minor defeat at Kraśnik, but success came next when the Russians successfully advanced into Austrian Galicia, with the Russian casualties of about 200,000, the Austrians having roughly twice the casualties, including thousands of POWs. For the huge successes at the front, he was awarded the Order of St. Vladimir, 1st class with swords, and the Order of St, George of the 2nd degree, being three of the only generals that were awarded this high decoration, the other two generals being General Nikolai Ruzsky and Nikolai Yudenich. During the battle at the Vistula River, he with his Southwestern Front armies (4th Army and the 9th Army), together with the Northwestern Front commander-in-chief General Ruzsky with his armies (2nd Army and the 5th Army) from the North. In the matter of a month, General Ivanov and General Ruzsky's troops successfully repulsed the German advance, taking about a hundred kilometres of land. Later on, General Ivanov commanded an operation towards Kraków, it was successful at first, but was later ordered to retreat, ending the initial success.
In early 1915, General Ivanov gained approval of the Stavka to launch an offensive towards Hungary, but the offensive was disturbed by the Germans in Poland. Furthermore, the Austro-German forces launched an offensive in southern Poland. During the battle, the Russians suffered casualties up to 350 thousand men, and the Russians were pushed out of Galicia, starting the Russian Great Retreat. General Ivanov repeatedly showed examples of poor leadership of the troops and indecisiveness, much like many other Russian generals at that time. Most particularly, he and the General Radko Dimitriev (commander of the 3rd Army) didn't make any effort to strengthen the 3rd Army, which the Austro-German forces inflicted the main blow at and nearly wiping the army.
Later in June, General Ivanov ordered General Nikolai Khodorovich, commander-in-chief of the Kiev Military District, to take 1 in a 1000 local German civilians as hostages, and imprison them for the rest of the war. General Ivanov also prescribed to requisition that all the German hostages could only have a small portion of food of all the supplies they had got, and the hostages were settled in a highly secured residence. And if any hostages didn't follow the orders, they would be met with death penalty.
Later at the end of 1915, he conducted a failed operation by the 11th Army against the enemy's forces. And in March 1916, he was replaced by General Aleksei Brusilov as the commander-in-chief of the Southwestern Front, he was then appointed a member of the State Council, and was made adjutant to tsar Nicholas II himself. General Brusilov recalled that, when he arrived and accepted the post, General Ivanov burst into tears and said that he couldn't understand why he was to be replaced. General Brusilov assumed that it was due to the fact that General Ivanov was too passive, who believed that the front couldn't succeed.
General Ivanov, with his loyalty towards the tsar and surprisingly the tsarina Alexandra Feodorovna and the mystic Rasputin as well, he enjoyed great confidence and reputation from the royal family. After General Mikhail Alekseyev was appointed chief of staff to the supreme commander-in-chief in mid 1915, which was the tsar himself, the tsarina wrote a letter to her husband, advising him not to let Alekseyev the only person in charge of the Stavka and advised him to let Ivanov to assist him, saying that:
You will be more relaxed, and Alekseyev will not bear one responsibility.
Further actions showed that it was Ivanov was the mastermind behind Alekseyev, who was not trusted by the tsarina. In return, Ivanov was treated very well by Nicholas. Later on, the tsar wrote to his wife:
I am very glad to see old Ivanov. Fortunately, he grumbled less than ordinary. He asked you to send him your new photo; please do it - it will calm the glori
Nikolai Iudovich Ivanov