In 1957 Defence Minister Duncan Sandys had a White Paper on the Ministry of Defence written up that called for major restructuring of the Armed Forces due to the fiscal realities of the nation, changes in Britain's position in relation to the rest of the world (loss of hegemony punctuated by the Suez Crisis a few years prior, decolonisation and the beginnings of Continental European integration) and the coming of the missile age. According to White Paper, the British Army was to be reduced in size and reorganised to reflect the ending of National Service and the change to a voluntary army, and to "keep the Army abreast of changing circumstances, policies, weapons and techniques of war". 51 major units and a large number of smaller ones were to be disbanded or amalgamated, leaving the army with a strength of 165,000 officers and men. The process was to be carried out in two phases, to be completed by the end of 1959 and 1962 respectively.

The reorganisation was done as such:

The Royal Armoured Corps was to be reduced by the amalgamation of: 1st King's Dragoon Guards and the Queen's Bays (2nd Dragoon Guards) as 1st The Queen's Dragoon Guards, 3rd The King's Own Hussars and 7th Queen's Own Hussars as Queen's Own Hussars, 4th Queen's Own Hussars and 8th King's Royal Irish Hussars as Queen's Royal Irish Hussars, 3rd Royal Tank Regiment and 6th Royal Tank Regiment, 4th Royal Tank Regiment and 7th Royal Tank Regiment, 5th Royal Tank Regiment and 8th Royal Tank Regiment

The Royal Artillery was to lose 18 major and numerous small units.

The Royal Horse Artillery was to be cut to three regiments.

The infantry of the line was to undergo major changes. Existing regiments were to be grouped in "brigades". Each brigade was to have a single depot with those of the individual regiments being reduced to the status of regimental headquarters. There was to be a reduction in the number of regular infantry battalions from 64 to 49 by the merging of pairs of regiments. The brigades and regiments were to be:

The Lowland Brigade: The Royal Scots, The King's Own Scottish Borderers, The Cameronians (Scottish Rifles) and a regiment formed by the merger of the Royal Scots Fusiliers and the Highland Light Infantry

The Home Counties Brigade: The Royal Sussex Regiment, The Middlesex Regiment and two regiments to be formed by the amalgamation of the Queen's Royal Regiment (West Surrey) with The East Surrey Regiment and The Buffs (Royal East Kent Regiment) with The Queen's Own Royal West Kent Regiment.

The Lancastrian Brigade: The Loyal Regiment (North Lancashire), and three amalgamated regiments formed by The King's Own Royal Regiment (Lancaster)/The Border Regiment, The King's Regiment (Liverpool)/The Manchester Regiment and The East Lancashire Regiment/The South Lancashire Regiment

The Fusilier Brigade: The Royal Northumberland Fusiliers, The Royal Fusiliers and The Lancashire Fusiliers

The Midland Brigade: The Royal Warwickshire Regiment, The Royal Leicestershire Regiment and The Sherwood Foresters

The East Anglian Brigade: Three regiments were to be formed by amalgamation of The Royal Norfolk Regiment/The Suffolk Regiment, The Royal Lincolnshire Regiment/The Northamptonshire Regiment and The Bedfordshire and Hertfordshire Regiment/The Essex Regiment

The Wessex Brigade: The Gloucestershire Regiment, The Royal Hampshire Regiment and two regiments formed by amalgamation of The Devonshire Regiment with The Dorset Regiment and The Royal Berkshire Regiment with The Wiltshire Regiment

The Light Infantry Brigade: The King's Own Yorkshire Light Infantry, The King's Shropshire Light Infantry, The Durham Light Infantry and a regiment formed by a merger of the Somerset Light Infantry and The Duke of Cornwall's Light Infantry

The Yorkshire Brigade: The Green Howards, The Duke of Wellington's Regiment, The York and Lancaster Regiment and a regiment formed by the merger of The East Yorkshire Regiment and The West Yorkshire Regiment

The Mercian Brigade: The Cheshire Regiment, The Worcestershire Regiment and a regiment formed by the merging of The North Staffordshire Regiment (Prince of Wales's) with The South Staffordshire Regiment

The Welsh Brigade: The Royal Welch Fusiliers, The South Wales Borderers and The Welch Regiment

The Northern Irish Brigade: The Royal Inniskilling Fusiliers, The Royal Ulster Rifles and The Royal Irish Fusiliers

The Highland Brigade: The Black Watch, The Gordon Highlanders, The Argyll and Sutherland Highlanders and a regiment formed by the merger of The Seaforth Highlanders with The Queen's Own Cameron Highlanders

The Green Jackets Brigade: The Oxfordshire and Buckinghamshire Light Infantry, The King's Royal Rifle Corps and The Rifle Brigade

The Parachute Regiment was to continue to have three battalions.

The Royal Engineers would be reduced by approximately 15,000 officers and men, with divisional engineer regiments to be replaced by field squadrons. The Royal Signals was to lose 13,000 soldiers by reduction of second-line units. Some of the work of the Royal Army Service Corps was to pass to civilian contractors, allowing a loss 18,000 men. The Royal Army Ordnance Corps was to lose 11,000 soldiers, and was to be organised more efficiently with a large number of depots closed. The Royal Electrical and Mechanical Engineers was to lose 23,000 soldiers. Other arms and services were to be reduced in proportion.

The restructuring of the Armed Forces was continued on the reccomendations of the 1966 Defence White Paper, written up under the Labour government of Harold Wilson which set the tone for British military functioning as a junior power the United States within NATO during the Cold War. This status as a junior power was definitively laid out by the commitment that the UK, "would not undertake major operations of war except in co-operation with allies." However it did maintain Britain's commitment to retaining a military presence in Malaysia and Singapore.

However, in 1967 and 1968 there was an economic crisis and the pound was greatly devalued leading to addenda to the White Paper calling for withdrawal of British troops from Aden in Yemen, Singapore, Malaysia, Cyprus, Malta, Libya and the Persian Gulf. These changes actually caused quite an outcry from the Tory parliamentary opposition and the wider public since it was an explicit reversal of Wilson's election pledge to maintain a British presence East of the Suez.