John Kerry has boldly gone on the offensive, heading straight for President Bush's "national security" stronghold, just like as a young naval lieutenant in Vietnam he turned the guns of his patrol boat to face the enemy.
It is ironic that he is now trying to redeem the Vietnam War. He is using, as evidence of his fitness to be president, his combat experience in a conflict which he questioned before he enlisted and which he opposed when he returned home.
Kerry: reminded voters of his experience of war
His speech sought to tell the world what kind of president he would be. He seems to be aiming more for the style of a Kennedy (another JFK) than a Clinton, and certainly not for that of a Jimmy Carter.
It is a risky strategy. He lays himself open to the Republican charge that he is inconsistent.
And Kennedy of course called on Americans to "pay any price, bear any burden" in the defence of liberty. John Kerry is certainly not going that far.
In fact, he is asking others to help share that burden. Perhaps underneath he is more like the pragmatic Bill Clinton.
But it is a necessary strategy. The subtle anti-war message of the Democrats is not enough for the undecided voters. John Kerry has to show himself as a man they can trust to be tough.
The convention speech does not have to lay out detailed policies. It does have to show which audience the candidate is talking to - the committed people in the hall or the uncommitted in the home. John Kerry chose the latter.
And yet, in presenting himself to be someone who can be tough when need be, he also wanted to show that he is not as ideologically driven as the Bush team.
He is offering not a softer foreign policy, but what he calls a "smarter" foreign policy.
First, he says he would not get into war so easily as Mr Bush.
The two key quotes from his convention speech in this context were: "I will be a commander-in-chief who will never mislead us into war" and "I will bring back this nation's time-honoured tradition: the United States of America never goes to war because we want to, we only go to war because we have to."
Second, he claims that he would fight the war on terror more easily because he would form alliances.
This concept of rebuilding alliances seems to be a central theme of his approach to foreign policy.
"We need to make America once again a beacon in the world. We need to be looked up to and not just feared," he said.
But of course that is easier said than done.
And on the issue of Iraq, building an alliance is about all he offers.
The section on Iraq in his speech is extremely brief: "I know what we have to do in Iraq. We need a president who has the credibility to bring our allies to our side and share the burden, reduce the cost to American taxpayers, and reduce the risk to American soldiers. That's the right way to get the job done and bring our troops home."
Quite who these allies are who are going to rush in to help is unclear. And exactly when the troops will come home is left open.
Iraq: Kerry wants help, but from whom?
Iraq is a big hole in his policy portfolio.
Another message John Kerry was trying to get across was that there would be a change of style. He could not go too far in his speech on this for fear of upsetting voters who do not want their government to "go wobbly" as Mrs Thatcher once warned President Bush senior against.
That does not stop his aides from being more open.
James Rubin, a state department spokesman from the Clinton era and now on the Kerry team, said in an interview with Newsweek magazine that John Kerry would sit down with other leaders before demanding action.
"He will do that in a way that expresses understanding for other people's points of view, that involves listening and leading rather than alienating, and that involves old-fashioned persuasion and an appreciation for other cultures and other values.
"And the bullying of the Bush administration will come to an end," said Mr Rubin.
This idea of building alliances would be taken into other fields, though how far that would go again remains to be determined.
Take the Kyoto agreement on climate control as an example.
President Bush dismissed it out of hand, displaying contempt for it in the presence of the German Chancellor Schroeder.
Senator Kerry has been praised by environmental groups for his voting record. Yet he is not committed to ratifying the Kyoto targets. His campaign website says this:
"When John Kerry is president, the US will re-engage in the development of an international climate change strategy to address global warming, and identify workable responses that provide opportunities for American technology and know-how."
It is all pretty general stuff
That does say something. But it does not say much.
He is keeping his options open to do something but not everything.
On other issues, one should not expect too much change. If change came, it would be in response to specific crises.
In the Middle East, a Kerry administration would remain a strong supporter of Israel. The Democratic Party platform actually begins its section with such a pledge.
On the old issue of Cuba, again not much is offered beyond an effort to "support effective and peaceful strategies to end the Castro regime..."
Presidential candidates, aware of the strength of the Cuban exile vote in the state of Florida (where the election was decided last time round) have no room for manoeuvre.
Africa is promised the "weight of American leadership to bear against the [HIV/Aids] crisis" without specific commitments.
On Europe, the aim is "revitalising the Atlantic partnership".
In Asia, there is a re-commitment to the "One China" policy with a vague promise to get China to adhere to "human rights standards".
It is all pretty general stuff.
Ambiguity is often said to be a hallmark of John Kerry's career. He is continuing that theme in many of his policy promises. This is what he has said about the International Criminal Court, which Mr Bush refuses to join:
"I support US participation in the International Criminal Court, but also believe that US officials, including soldiers, should be provided some protection from politically motivated prosecutions."
That says a lot about John Kerry. You don't quite know how far he will go.