The head of the armed forces has backed the Government's defence cuts, insisting that it was essential that military spending matched the nation's economic resources.
General Sir David Richards, the Chief of the Defence Staff, said that a military plan which did not take account of the resources available was nothing more than a "wish list".
But at a speech to the Policy Exchange think-tank in London, he warned that the long-term plans depended on a return to real terms increases in defence spending after the current round of cuts is over in 2015.
Gen Richards, making his first public speech since taking over as CDS last month, acknowledged that the Strategic Defence and Security Review (SDSR) involved "calculated judgments" over which military capabilities should be cut.
However he said that it was essential to understand that a country's military strength was underpinned by its economic strength.
He pointed to the collapse of the Soviet Union after it went bankrupt trying to match US defence spending as an example of the consequences when a nation gets the balance wrong.
"A plan is not a plan if it doesn't take into account the resources available. It is a wish list and no general worth his salt bases his plan on wishful thinking," he said.
"This SDSR has been no different and builds on the reality of the position in which we find ourselves. That of course has required us to make judgments that trade the perfect for the acceptable.
"The review prioritises on the basis of our assessment of risk. It ensures we never fall into the trap of gambling.
"We cannot prepare for everything. We cannot be instantly ready for every eventuality. But we can be prepared, in close concert with allies, for the most likely contingencies and structured and equipped to deal with the greatest threats."