BBC Chief Diplomatic Correspondent
Tony Blair insists Britain must continue to show its willingness to launch military interventions.
It was a very robust defence of the notion that we can do two things at once - that we can exert what the prime minister calls soft power and hard power.
Tony Blair spoke of increased military expenditure
We can pursue climate change, world poverty and the Middle East peace process while still being able and willing to project British military power, in the interests of British and global security.
The prime minister spoke at length about the post-9/11 world, showing that he remains concerned that his oft-repeated explanations about how Britain can meet its security challenges have, in certain quarters, fallen on deaf ears.
He compared Islamic terrorism to "revolutionary Communism in its early and most militant phase," and dismissed as "ludicrous" the argument that his policies had served to inflame Muslim opinion.
This was a highly personal speech, in which Mr Blair emerged as an unrepentant exponent of what he would see as enlightened interventionism.
He made it clear that to retreat in the face of today's threats into what he described as "an unstated, passive disengagement" was unacceptable. Without "hard" power, he says, Britain's role in the world is diminished.
One of Mr Blair's problems has been that his highly visible, endlessly analysed interventions have been conducted at a time when the distance between the military and society as a whole is as great as it has ever been.
In the decades since the end of conscription, and with the armed forces shrinking, fewer and fewer people have any contact with or understanding of what life in the military is all about.
While saying that in his view Britain's armed forces were "superbly equipped," he did acknowledge that throughout the course of these military adventures of recent years, if you "talk at any length to serving soldiers there will be, amongst the pride, some anger at faulty weapons and ammunition; boots and body armour".
There was a recognition that military operations have put the British military under a great deal of stress.
Tony Blair gave his speech on HMS Albion
Towards the end of his speech, Mr Blair said that renewing the "covenant between Armed Forces, government and people" would involve "increased expenditure on equipment, personnel and conditions of our armed forces".
He said this would be for the long-term, not in the short run.
In other words, no pledges of additional cash now, but a hint that the Armed Forces might get a decent settlement from Gordon Brown's comprehensive spending review in the summer, assuming the prime minister and chancellor see eye to eye on this area of policy.
The prime minister spoke about the future of the Navy, and the choice of venue on Friday was significant.
He gave his speech from the bowels of the amphibious assault ship HMS Albion, one of the navy's newest vessels and the embodiment of the sort of expeditionary capability the prime minister is so keen on.
And he said that among the projects coming through were new carriers twice the size of our existing ones.
That will go some way towards assuaging the doubts of those who remain sceptical that the government does not intend to carry out its ambitious plans for two so-called "super-carriers".