At the time of partition, Usman being a Muslim officer in the Baluch Regiment, was under intense pressure from the newly born Pakistan’s leadership to opt for the Pakistan army. But so strong were his ideals of his motherland that even the ultimate bait of becoming the Pakistan Army Chief proved unsuccessful in convincing Usman.
When the Baluch Regiment was allotted to the Pakistan army, Brig Usman was transferred to the Dogra Regiment. But war had already been thrust upon India when Pakistan sent tribal irregulars and its soldiers into Jammu & Kashmir. Even as the situation in the Kashmir valley stabilised the threat continued to be serious in the Jammu region. Brig Usman, commanding 77 Parachute Brigade, was sent to command the 50 Paraachute Brigade, deployed at Jhangar in December 1947. On 25 December 1947, with odds heavily against him, Jhangar was wrested by the Pakistanis. Located at the junction of roads coming from Mirpur and Kotli, Jhangar was of strategic importance, but more compelling was Brig Usman’s fierce pride in his men and determination to restore their honour. On that day the brigadier took a vow to recapture Jhangar – a feat he accomplished three months later, but at the cost of his own life.
During the defence of Naushera against overwhelming odds and numbers, his fiery leadership had resulted in major defeat of the enemy at and around Naushera with 2000 casualties [about 1000 dead and 1000 wounded] while he suffered only 33 dead and 102 wounded. That battle earned him the title Naushera ka Sher. The same Pakistanis, who had earlier tried to motivate him to join the Pakistan Army and make him its chief, announced a then astronomical sum of Rs 50,000 as a prize for his head, in 1948. Unaffected by praise and congratulations, the Brigadier continued to sleep on a mat laid on the floor as he had vowed that he would not sleep on a bed till he recaptured Jhangar, from where, outnumbered by a large force of infiltrators inducted by Pakistan Army, he had to withdraw earlier.
The then Lieutenant General K M Cariappa [later General and C-in-C, Indian Army/Chief of Army Staff and years after retirement made Field Marshal], who had taken over as Western Army Commander, brought his tactical headquarters forward to Jammu to oversee the conduct of two important operations, the capture of Jhangar and Poonch. The capture of Jhangar was of special significance for Brig Usman. The operation commenced in the last week of February 1948. 19 Infantry Brigade advanced along the Northern ridge, while 50 Para brigade cleared the hills dominating the Naushera-Jhangar road in the south.
The enemy was eventually driven from this area, and Jhangar was recaptured. Pakistan brought its regular forces into the fray in May 1948. Jhangar was once again subjected to heavy artillery bombardment, and many determined attacks were launched on Jhangar by the Pakistan Army. Brig Usman however frustrated all enemy attempts to recapture Jhangar. It was during this arduous defence of Jhangar that Brig Usman was unfortunately was killed on July 3, 1948, by an enemy 25-pounder shell. His last words were ‘I am dying but let not the territory we were fighting for fall for the enemy”. For his inspiring leadership and great courage, he was awarded the Maha Vir Chakra posthumously. 
The nation was so overwhelmed by the sacrifice of Brigadier Mohammad Usman that Prime Minister Jawaharlal Nehru and his Cabinet colleagues attended the funeral of the hero — “the highest ranking military commander till date” to lay down his life in the battlefield. He was given a state funeral of a martyr. 
A man of simple taste and a teetotaller, Usman remained a bachelor throughout his life. He used to donate a large part of his salary to support poor children and pay for their education. Brig Usman was indeed an epitome of valour, a great patriot and nationalist.