Former commander of the Joint Forces Command, general Sir Richard Barrons has delivered a scathing assessment of the UK military in a 10 page private memorandum to defence secretary Sir Michael Fallon.
Richard, who left his post in April, said the armed forces would not be able to protect the country from an attack by a serious military power.
His criticism comes after the government’s decision to increase defence spending by nearly £5bn by 2020/21 and to meet Nato’s target to spend 2% of GDP on defence for the rest of the decade.
In his memo, Richard said: “Capability that is foundational to all major armed forces has been withered by design.”
He added: “There is a sense that modern conflict is ordained to be only as small and as short term as we want to afford - and that is absurd.
“The failure to come to terms with this will not matter at all if we are lucky in the way the world happens to turn out but it could matter a very great deal if even a few of the risks now at large conspire against the UK.”
The document, seen by the Financial Times, gives a withering judgment of the country’s ability to defend itself against a full-scale military attack and singles out Russia, a country seen as more dangerous and unpredictable since its annexation of the Crimea and incursion in Ukraine.
Richard said: “Counter-terrorism is the limit of up-to-date plans and preparations to secure our airspace, waters and territory ... there is no top-to-bottom command and control mechanism, preparation or training in place for the UK armed forces (to defend home territory) ... let alone to do so with Nato.”
On Britain’s ability to defend itself from aerial attack, he said: “UK air defence now consists of the (working) Type 45 (destroyers), enough ground-based air defence to protect roughly Whitehall only, and RAF fast jets.
“Neither the UK homeland nor a deployed force - let alone both concurrently - could be protected from a concerted Russian air effort.”
His critique has been supported by major general Tim Cross, who served in the Army for nearly 40 years.
Major general Cross also rejected suggestions Richard’s comments were a case of “sour grapes” because he was overlooked for promotion.
“Like all commanders, and I did this myself when I handed over command of my division, what Richard has done is produce what we call a haul down report,” he told BBC Radio 4’s Today programme.
He added: “He’s speaking truth into power and it’s a normal thing to be doing.”
