Mr Cameron seems to have forgotten one of Rome’s greatest lessons – If you want peace, prepare for war.
The Tory leadership is yet again heading for a damaging internal row, this time over defence spending.
Many on the Right are appalled at the prospect that if the Conservatives win a majority in May, Mr Cameron and Co will once again swing the axe, cutting men and equipment.
This action would slash the amount spent on our armed forces to a level that not only falls well below Nato’s two per cent floor target but, more importantly, results in the loss of many vital capabilities.
Already UK forces are wholly reliant on the French and Canadians for submarine-hunting aircraft after a decision was taken to scrap the country’s fleet of Nimrods under the 2010 defence review.
The decision to sell our Harriers to that minor military power, the United States, highlighted not only the folly of the policy of scrapping them, but also ensured that the UK will have aircraft carriers, but no planes capable of flying from them, until at least 2018. A deployable force is not expected much before the next decade.
The party’s leadership, including the usually sound Philip Hammond, tries to justify this by saying there are “no votes in defence”.
Yes, you can make this argument if you ask voters to rank defence against a list of other priorities. Indeed, in a recent poll by ComRes, asked which three policies should be included in the parties’ manifestos, only one in 20 people (five per cent) opted for increased spending on the military.
The same level of support was found for protecting international aid (five per cent).
The two issues were one percentage point above continuing the policy of austerity (four per cent) and legalising drugs (four per cent).
This compared with 60 per cent who wanted to protect the NHS, nearly half (46 per cent) who backed a cap on immigration, and just over a quarter (26 per cent) who wanted an EU referendum.
What these figures hide is that support for defence spending is highest among Tory voters and those seats that have military establishments.
Ask this question in marginal seats in Portsmouth, Plymouth, or Scotland and the response would be very different.
And if defence was not an issue, why did Mr Cameron visit Afghanistan no fewer than 13 times since becoming the Conservative leader in 2005? Surely not just for a few photo-ops?
Or why did the PM, to his credit, go out of his way to ensure the Military Covenant was enshrined in law by the Armed Forces Act 2011?
It matters too if you subscribe to the Hobbesian view of the State, the price the Government pays for being in charge is to protect us all from harm, both foreign and domestic.
The last time we lost sight of this was in 1981 when, under Secretary of State for Defence John Nott, a devastating White Paper was produced that aimed to rip the heart out of the Royal Navy in the cause of cutting spending.
Famously, this led to the removal of HMS Endurance, the ice breaker based in the Falklands, emboldening the military junta in Argentina and leading to war just 12 months later. The irony was had the cuts to the armed forces been fully enacted, then recapturing these British Islands would have been impossible and Margaret Thatcher would almost certainly have lost the election in 1983.
No, defence does matter and it is folly of the worst kind to think that it does not. Those on the Right know this, especially those who have served. This is why even so close to an election they are willing to press Cameron and Osborne on a cast iron commitment to honour our national obligations.
And they are willing to have a row on this issue. They are not prepared to gamble with defence of the realm and if Mr Cameron is not then do well to remember these words sometimes attributed to Julius Caesar, “Si vis pacem, para bellum”.