Kalaitović became active in resistance to Axis occupation of Yugoslavia in August 1941. On 25 August, together with units of voivode Đekić and Vlajko Ćurčić he participated in capture of Axis controlled Kokin Brod when all members of its garrison were killed. His deputy was Borislav Mirković. Kalaitović almost certainly participated in the Battle of Nova Varoš on 5 September 1941.
Establishment of the Mileševa Corps
On 29 October 1941 Kalaitović attended the gathering of people from villages Štitkovo, Božetić and Bukovik, organized by Chetnik officer Božo Javorski. In February 1942 joint forces of Chetniks under command of Kalaitović and Muslim militia commanded by Hasan Zvizdić attacked the Communist forces. In Autumn of 1942 the organization of the Chetnik units in valley of the riverLim was changed, based on the iniciative of Pavle Đurišić, and Mileševa Corp was established. During one battle with communist forces, Chetniks commanded by Kalaitović captured 120 enemy soldiers and discovered that 22 of them wore uniform of Ustaše, to whom they belonged before they joined the communists, and immediately executed them.
Participation in Đurišić's raids of revenge
On January 5, 1943, Montenegrin Chetniks, commanded by Pavle Đurišić, attacked 33 villages predominantly populated with Muslims in the region of Lower Bihor. They pursued raids of revenge against Sandžak Muslims, many being innocent villagers, with the goal of settling accounts with Muslim militias. In February 1943, Chetnik units commanded by Kalaitović, together with those commanded by Ostojić, Baćović, Đurišić and Lukačević killed about 1,200 Muslim Militiamen and about 8,000 women, children and old people.
Retreating with Đurišić toward Slovenia through Bosnia
Mileševa Corp with 200 men at that time commanded by Kalaitović joined retreating units of Pavle Đurišić at the end of 1944. On 16 December 1944 his units were ambushed near Miljevina and suffered substantial casuatlies that left him unable for further actions. The Chetnik units were restructured against the order published on 5 January 1945, but Mileševa Corps remained non-restructured and under command of Kalaitović and among other Chetnik units of Chetnik HQ for Montenegro, Boka and Old Ras. Kalaitović and his units participated in the Battle of Lijevče Field.
Leaving Đurišić and return to Štitkovo
After the battle, Kalaitović and group of his Chetniks retreated from the region of Banja Luka with intention to return to Sanjak region. They left Đurišić on 9 April 1945. Kalaitović was one of Chetnik commanders who survived defeat of Chetnik forces on Zelengora on 13 May 1945.
Legacy
In 2010 a monument dedicated to Kalaitović was placed in the village of Štitkovo on the Kalaitović family estate. Serbian historian Salih Selimović states that Kalaitović protected the Muslim population and never attacked any of Muslim localities within the zone of his responsibility. When, during 1945, Communist authorities discovered that Kalaitović was hiding in the village of Kladnica, they blocked the area, but Muslim villagers helped Kalaitović to hide and escape. Serbian historian Dubravka Stojanović objected to the monument in Štitkovo because Kalaitović's units did commit war crimes. In 2013 a memorial plague to 108 Chetniks who died in the World War II was placed in Štitkovo.
