Following his time with Special Forces, he became commanding officer of the 1st Battalion, Grenadier Guards from 2008 to 2010.[5][10] He was promoted to lieutenant colonel on 30 June 2008.[11] With the Grenadiers, he served a tour in Afghanistan, during which the Ridgeback PPV in which he was travelling was blown up by an improvised explosive device (IED): all six soldiers inside escaped uninjured, but the vehicle was thrown into the air, had its wheels blown off and its armour shredded.[10] Walker was awarded the Distinguished Service Order (DSO) in September 2010 in recognition of gallant and distinguished services in Afghanistan.[12]
Walker served as Colonel Commandant of the Royal Army Veterinary Corps from 1 March 2017 to 1 June 2022,[18] and Regimental Lieutenant Colonel of the Grenadier Guards from 18 June 2017 to 18 June 2022; both ceremonial appointments.[19][20] He was Honorary Colonel of the Cambridge University Officers' Training Corps until June 2024.[21]
He was appointed Colonel Commandant of the Honourable Artillery Company on 30 May 2024.[22]
Chief of the General Staff
It was announded in December 2023 that Walker had been selected to be the next Chief of the General Staff, the professional head of the British Army, and would take up the post in June 2024.[23][24] He took up the post on 16 June 2024. On the same day, he was promoted to general and appointed Aide-de-camp general to the King.[25]
On 23 July 2024, Walker warned of the threat posed by Russia, China, Iran and North Korea.[26] He said the UK must be prepared for a possible war with Russia by 2027.[27]
Walker said there were "no winners" in Russia's invasion of Ukraine, adding that "it is an utter devastation for both sides and lost generations."[28] He said that with the current way of fighting, it would take Russia five years to control the four regions of Donetsk, Luhansk, Kherson and Zaporizhia that Russia claims as its own, and it would cost Russia more than 1.5 million casualties.[29] He said: "It doesn’t matter how it ends. I think Russia will emerge from it probably weaker objectively – or absolutely – but still very, very dangerous and wanting some form of retribution for what we have done to help Ukraine."[30]
Personal life
In 1998, Walker married Kate White-Thomson. They have three daughters and live in Herefordshire.[5]