The British Army’s Strike Experimentation Group will this year begin exploring a mixed brigade-size fleet of tracked and wheeled armoured vehicles as it continues to pursue a separate approach to a ‘medium-weight’ combined-arms brigade than that adopted by the United States and French armies.

By Brigadier (Retd) Ben Barry, Senior Fellow for Land Warfare

The US Army and French Army have ’medium weight‘ combined-arms brigades equipped with families of wheeled armoured vehicles that can move rapidly on roads over long distances. The British Army currently lacks such formations, a gap the 2015 Strategic Defence and Security Review (SDSR) identified and moved to address.

The 2015 SDSR required the UK to regenerate its military capability for large-scale war fighting, and part of this included the formation of two ’strike brigades‘, increasing the overall number of army deployable brigades from four to five. These were to be formed, in part, by ‘re-roling’ one of the existing armoured infantry brigades.

These new brigades are to be organised as follows:

  • One regiment (battalion size) of Ajax in the reconnaissance role;
  • A second regiment of Ajax in the ’medium armour role’. This is a new concept for the British Army and sees Ajax acting as a medium-weight tank;
  • Two battalions of mechanised infantry;
  • Artillery, combat engineer, logistic and medical units.

The strike brigades’ infantry battalions will use a yet to be procured Mechanised Infantry Vehicle (MIV), which is planned to be an existing wheeled armoured personnel carrier.  The army wants to introduce the MIV as a soon as possible; however, a vehicle has yet to be selected and no delivery schedule has been announced. The other major fighting vehicle for the strike brigades is to be the Ajax tracked armoured reconnaissance vehicle. The Ajax is based on the General Dynamics ASCOD 2.

While the new wheeled MIV will offer British strike brigades’ infantry battalions a degree of mobility equivalent to similar French or US formations, the tracked Ajax vehicle, although well protected and possessing tactical cross-country mobility, is likely to travel more slowly over operational and long distances. Compared to their US and French equivalents, the UK’s strike brigades are unlikely to be able to move complete brigades as fast over longer ranges. For example, in their 2013 intervention in Mali, a French battalion equipped with the VBCI wheeled infantry fighting vehicle was able to cover a distance of 2,000 kilometres in five days.

In response to the worsening security environment in Europe and the emergence of Russia as a strategic rival, the 2015 SDSR placed two core requirements on the army: rebuilding its capability to field a full division of three brigades and to get more deployable brigades out of the forces it has. The army’s only deployable division, the 3rd Division, is being re-organised from a three-brigade formation into one of four brigades: two existing armoured infantry brigades and the two strike brigades.

Irrespective of SDSR 2015, it also appears that the number of Challenger 2 main battle tanks in front-line service will further reduce, from three battalion-sized regiments to two, with one regiment swapping its tanks for Ajax. Given the renewed importance of the tank as demonstrated in the wars in Iraq and Syria and in the fighting in eastern Ukraine – and the British Army’s visible commitment to the forward defence of Eastern Europe – this could be seen as a counter-intuitive reduction in anti-armour capability. But some of the risk involved is mitigated by the army funding a major life-extension programme for Challenger 2 that promises to make the tanks it has more effective.


This analysis originally featured on the Military Balance+, the new IISS online database that enables users in government, the armed forces and the private sector, as well as academia and the media, to make faster and better-informed decisions. The Military Balance+ allows users to customise, view, compare and download data instantly, anywhere, anytime.

Back to content list

Blog Homepage

The Military Balance Blog

Posts from the IISS Defence and Military Analysis programme.

Latest Posts

The Military Balance 2017

The Military Balance is the authoritative assessment of the military capabilities and defence economics of 171 countries.