It came a day after they had papered over their own differences to trumpet an agreement on curbing greenhouse gas emissions -- slammed by environmental groups as meaningless because it contained only "aspirational" goals.
As the leaders headed home, workers started dismantling the huge fence and other measures that had locked Sydney in the biggest security straitjacket in Australian history.
Australian Prime Minister John Howard apologised but said residents should not blame the visiting politicians or his government for the security surrounding the Asia Pacific Economic Cooperation (APEC) summit.
"It's the fault of those people who would threaten to resort to violence in order to disrupt the meeting," he told reporters. State police commissioner Andrew Scipione was unapologetic: "I'd rather be criticised for overkill than not have enough resources."
The main security scare came when a team from a satirical comedy TV show, one dressed as Osama Bin Laden, breached a security cordon to get within 10 metres (yards) of the hotel where Bush was staying.
Fighter jets also Sunday intercepted a light plane whose pilot mistakenly breached a no-fly zone extending some 80 kilometres (50 miles) around central Sydney.
Standing in front of most of the other APEC leaders -- US President George W. Bush had left a day early to return to Washington -- at the conclusion of the summit on Sunday, Howard said all sides had to compromise on trade.
He said they were sending "an urgent request for all countries involved in the Doha round to renew their efforts to achieve an outcome, emphasising that agriculture and industrial products are the two priority areas."
World Trade Organisation chief Pascal Lamy has been in Sydney to lobby for support from the APEC economies, including the United States, China and Japan, for the trade talks, known as the Doha round.
The WTO member states are arguing over the size of cuts in barriers to trade in agriculture, industrial goods and services amid fierce disagreements between rich and poor countries over what concessions to make.
Howard said the talks "still represent the last best hope for an aggregate multilateral trade agreement."
On Saturday, APEC leaders issued their flagship announcement, an agreement setting non-binding goals on reducing energy intensity and increasing forest cover as part of the wider fight against global warming.
Howard hailed it as "by far the most important statement" to emerge here, but Greenpeace Southeast Asia energy campaigner Abigail Jabines branded it "a political stunt.
"Developing nations of the Asia Pacific region cannot afford to accept lip service instead of action," she said.
A testy Howard retorted that "it was unrealistic to expect that out of this meeting we would have binding targets," saying critics were either "ignorant" or pushing their own political agenda.
The APEC leaders also promised to increase cooperation on a range of other concerns ranging from contaminated foods, pandemics and intellectual piracy to regional security and the fight against terrorism.
Conference sources said the reference to contaminated products, while long an APEC concern, had added significance amid international fears over a spate of recalls of Chinese foodstuffs and other goods.
Howard also said APEC would not consider admitting any new members until at least 2010, meaning India will remain out in the cold.
He said the summit would be hosted by the United States in 2011 and Russia one year later, after summits in Peru next year, then Singapore and Japan in 2009 and 2010.