Several equipment failures and bungled procurement deals raise questions about the condition and readiness of the UK armed forces to deal with a serious military attack, a report has warned.
An investigation by the Sunday Times revealed that the Royal Navy's Type 45 destroyers are so noisy that they can be detected by enemy submarines at a distance of up to 100 miles (160km).
The six Type 45 warships have also been beset by engine problems, which cause them to shut down completely in warm waters.
Problems were also discovered in other weapons systems in the military, with the new Ajax light armoured vehicles found to be too big to fit into the A400m, the RAF's main transport vehicle.
In addition, a number of technical glitches have prevented the army's new 54 Watchkeeper reconnaissance drones from entering into full service – 12 years after they were ordered.
General Sir Richard Barrons, a former commander of Joint Forces Command, called on the government to "re-bench" the armed forces against the threat of a resurgent Russia by augmenting the UK's cyber and air defences.
He told the Times that years of defence cuts had the left the UK military with an "existential minimum" amount of equipment and stores.
"You are dealing with a legacy of iterative hollowing out, which has reached a point where the frog has boiled," Barrons said.
Rear Admiral Chris Parry, a former Ministry of Defence director of operational capability, criticised the government for pouring money into the Type 45's anti-aircraft and anti-missile systems without giving thought to the anti-submarine element.
He said the MoD had overlooked suppressing the noise of its warships after the Cold War ended as the threat from Russian submarines diminished.
"We have forgotten all about it – it's crazy. Noise suppression has been probably the biggest dirty secret since the end of the Cold War that people have been cheerfully ignoring," Parry told the Times.
The MoD responded to the report by pointing out that the UK had the largest defence budget in Europe.
"We are focused on maintaining an affordable programme and getting the best value for the taxpayer to deliver the cutting-edge kit our armed forces need to keep Britain safe," it said.