Russian President Vladimir Putin on Monday ordered the Russian Army to add 180,000 more troops, which would bring its total to 1.5 million active-duty soldiers — the second largest army in the world after China.

The order, which goes into effect on December 1, is the third major increase to the size of Russia’s military Putin has ordered since he invaded Ukraine in February 2022. He added 137,000 active-duty soldiers in August 2022 and 170,000 in December 2023.

With reserves and other personnel included, the Russian military will have 2.38 million members after Putin’s order goes into effect, increasing from 2.2 million.

“This is due to the number of threats that exist to our country along the perimeter of our borders. It is caused by the extremely hostile environment on our western borders and instability on our eastern borders. This demands appropriate measures to be taken,” Kremlin spokesman Dmitry Peskov said on Monday.

The Russian Defense Ministry said Putin’s decree for more troops was a response to NATO putting more troops and advanced weapons along Russia’s border.

Russian Deputy Defense Minister Alexander Fomin said last Friday that NATO is “making plans of sending their troops to Ukraine.”

“This is a dangerous game, which may lead to a direct military confrontation of nuclear powers,” Fomin said.

On the same day, Putin warned that if Western powers lift their restrictions on Ukraine using their long-range missiles to strike targets deep in Russian territory, it would mean “NATO countries,” including the United States, “are at war with Russia.”

Putin said the Ukrainian military “is not capable of using cutting-edge high-precision long-range systems supplied by the West” to hit targets in Russia without direct Western assistance.

The chairman of the defense committee in Russia’s Duma, Andrei Kartapolov, said on Monday that Russia needs to expand its military to deal with the growing security threat posed by NATO after Finland joined the alliance in April.

Foreign military analysts believe that a severe Russian manpower shortage is one reason the Ukrainians were able to counter-attack and seize territory in the Kursk region last month. Russia has about 700,000 troops involved in the Ukraine invasion, and has been reluctant to call up more reserves to bolster its forces, fearing civil unrest.