[12] He was deployed to the Former Republic of Yugoslavia in Spring 1996, promoted to colonel on 30 June[13] and awarded the Queen's Commendation for Valuable Service in November.

[16] Wall went on to serve as Chief of Staff of the National Contingent HQ in Qatar, overseeing UK operations in Iraq, from January 2003.

[28] On 15 September 2010 Wall took over the post from General Sir David Richards who became Chief of the Defence Staff in late October 2010.

[32] Amidst ministerial,[33] media and political pressure from both sides of the House,[33][34] Wall told an army magazine in April 2014 that lifting the ban on women serving in combat units was "something we need to be considering seriously."

It came to light that, under European law, the policy of preventing female soldiers from applying for certain jobs in the army was to be reviewed by 2018, and that the US, Australia, Canada, France, Germany, Holland, Denmark, Norway and Israel all allowed women to serve in combat units.

The Times had reported that his main motivation for changing this rule was showing potential female recruits that the army was an equal opportunities employer:[35] I want every woman in the country to know the service is open to them and we need to make sure we get that message across.

[40] Since leaving the army, Wall co-founded and is Chief Executive of a leadership and change consultancy, Amicus Limited.