At the Veterans of Foreign Wars convention last week, he accused Obama of placing the nation's security below "the ambition to be President".
But the ambitions stirring below created a market for a new breed of middle-class finishing schools.
I don't like heights and ballooning appears on my list of ambitions just below pot-holing and self-mutilation.
In effect, we would be using the 2015 agreement to set targets for some 15 years away, potentially locking in low ambition and putting the below-2C goal out of reach.
It is a glittering view of Rydal waterfall, in which he achieved his ambition of showing every pebble below the ripples of water, a painting full of light and happiness.
In a joint statement, the CEOs of BP, Shell, Saudi Aramco, Total, Repsol, Statoil, Eni, Petroelos Mexicanos, Reliance Industries and BG Group stated their ambition to keep global warming below a level many consider dangerous but fell short of outlining any clear goals towards this.
Diplomats from the 43 Caribbean, African and Pacific nations grouped as Aosis (Alliance of small island states) at the UN climate talks in Cancún said that they faced "the end of history" if rich countries did not raise their ambition to hold temperatures well below 2C.
The rise shows that Cameron's ambition of getting net immigration down below 100,000 is further away than ever.
"An ambition to keep global temperature rises below 1.5C is all very well, but we still don't have an adequate global plan to make this a reality.
An ambition to keep global temperature rises below 1.5C is a positive step forwards, but there is no real plan to make this a reality.
He became a soloist, one level below principal, just as his ambition to dance started to cool.
