The public should express its appreciation of Britain's military "more loudly and more proudly", David Cameron said ahead of next week's Armed Forces Day.
The Prime Minister said the country had a "social responsibility" to shows its thanks - invoking the spirit of the two world wars.
And he called for "an explosion of red, white and blue" across the country on Saturday when celebrations will be held across the country - with the main event in Cardiff.
Writing in the Sunday Telegraph, Mr Cameron said his recent trip to Afghanistan - his first as PM - had been a powerful reminder of the risks faced by troops.
And he said he was determined not to allow the conclusions of the Bloody Sunday inquiry to "cloud the reputation of our armed forces and the pride they inspire".
Citing a number of recent military heroes from the Afghan conflict, he said: "These people know all about duty - they've lived it. Now we as a country must do our duty by them.
"Over the past few years there's been an increasing appreciation of what our Armed Forces do.
"But still I believe that we should do more."
The Government was playing its part through policies such as doubling frontline troops' operational allowances, renewing the military covenant, improving health and housing services for families and better co-ordinating treatment for veterans suffering mental illness, he said.
"But supporting our Armed Forces isn't just a government responsibility - it's a social responsibility.
"In the First World War those at home didn't just sing 'keep the home fires burning', they practised it. In the Second World War, the military occupied a huge place in the national consciousness, partly because everyone knew someone in uniform.
"I believe as a country at war we should see the same appreciation today, with the military front and centre of our national life once again.
"There is huge respect for the Armed Forces community out there, and I want that expressed more loudly and more proudly. As someone once said, silent gratitude isn't much use to anyone - so next Saturday I hope we see an explosion of red, white and blue all over the country."
Mr Cameron won praise for his handling of the Bloody Sunday inquiry this week - apologising for what he said were the "unjustified and unjustifiable" actions of British soldiers in Londonderry.
"But those wrongs cannot be allowed to cloud the reputation of our Armed Forces and the pride they inspire," he wrote today.Reuse content