Educated in Dublin, Beckett was commissioned into the Queen's Royal Irish Hussars in 1984. After serving in the Gulf War in 1991 and Sierra Leone Civil War in 2001, he became commanding officer of 1st Battalion the Parachute Regiment in 2002 in which role he was deployed for the Invasion of Iraq in 2003. He became Deputy Director, Higher Command and Staff Course in 2005, Commander of 20th Armoured Brigade in 2007 (in which role he was again deployed to Iraq) and Director Commitments at Headquarters Land Forces in 2009. He went on to be Deputy Commander of the NATO Rapid Deployable Italian Corps in July 2010 in which role was deployed as Chief of Staff for the International Security Assistance Force in Afghanistan. Beckett retired in 2018.