Kerry sought to spell out how President Bush had failed to meet that test in Iraq: "[Bush] gave a speech in which he said, 'We will plan carefully. We will proceed cautiously. We will not make war inevitable. We will go with our allies.' He didn't do any of those things."
Bush seized on Kerry's "global test" remark, saying it revealed a weakness in Kerry's judgment. Bush said he would not allow foreign governments to have veto power over U.S. decisions on national security.
The exchange highlighted the contrast in how the two candidates view the exercise of U.S. power in the world. Bush and Kerry seem to differ sharply in their willingness to bind U.S. actions to the opinions -- if not the structures -- of the international community.
But the substance of either man's engagement with global treaties and institutions might not prove so different.
"My sense is that we're seeing a significant difference in emphasis, which is not necessarily a difference in kind," said Michael Doyle, an expert in international affairs who teaches at New York's Columbia University.
To be sure, the Bush administration has taken steps that have raised concerns about its commitment to international treaties. It "unsigned" the United States from the statute governing the International Criminal Court (ICC) and pulled the United States out of the Kyoto Protocol on climate change.
Kerry has signaled he would re-engage the United States in working on a global climate change strategy and soften Washington's stance on the ICC. But any moves toward Kyoto-type goals or accommodation to the ICC would likely face strong challenges in the U.S. Congress or by other domestic interests.
Meanwhile, the Bush administration, despite its unilateralist reputation, is now working closely with the United Nations on a wide range of security matters, including nation-building efforts in Iraq and Afghanistan.
After initially rebuffing the United Nations, the Bush administration backed a resolution in June that gives sweeping powers to the UN to lead in election and reconstruction efforts in Iraq. Kerry's proposals for Iraq are considered echoes of the current Bush plan.
Doyle said Bush's relations with the UN reflect a learning curve of sorts for the U.S. administration: "The Bush administration, after rather harsh rhetoric about the irrelevance of the United Nations, was back knocking on the UN's door to obtain as much UN assistance as it could in the stabilization and the peace-building effort in Iraq. There are certain logics that are hard to escape in world politics, among them that you really don't want to go it alone in many, many circumstances."
On trade policy, U.S. membership in the World Trade Organization (WTO) binds it to the body's dispute-resolution mechanism, meaning it is less able to retaliate unilaterally against other WTO members.
Bush has completed free-trade agreements with 12 countries. Kerry has pledged to review all trade agreements to strengthen labor and environmental standards.
This could result in a stalling of the bilateral-trade-agreement trend, said Kimberly Ann Elliott, a research associate at the Institute for International Economics, a U.S.-based policy institute. She said there might be tougher rhetoric from a Kerry administration on enforcing trade agreements with Europe, Japan, and China, but noted there are limits to what action he could pursue.
"A Kerry administration or even a second Bush administration can fulminate, and if they have a good case they can bring more of them before the WTO if they think that would be useful," Elliott said. "But there are limits to how aggressive you can get now on trade issues without violating WTO obligations."
The Bush administration, for its part, placed tariffs on steel imports in March 2002. It lifted them in December 2003 after the WTO's highest court ruled they violated global trade laws. Bush also signed a farm bill that markedly increased trade-distorting agricultural subsidies. But Elliott said Bush remains generally engaged on key free-trade issues, especially in his commitment to the WTO's Doha development round.
Perhaps the most fundamental difference between Kerry and Bush would be in how they would handle multilateral arms-control agreements.
The Bush administration withdrew from the 1972 Anti-Ballistic Missile (ABM) Treaty at the end of 2001. Bush followed up with negotiations with Russia that resulted in the Moscow Treaty, which aims to reduce U.S. and Russian long-range nuclear warheads by two-thirds by 2012.
Bush has declined to resubmit to Congress the Comprehensive Test Ban Treaty, which was rejected by the U.S. Senate five years ago. The Bush administration also rejected a protocol aimed at establishing an enforcement mechanism for the Biological Weapons Convention.
Many of these moves are seen as reactions to major shifts in the world of arms control. But there is also concern about a general weakening of arms control structures.
"Many of these treaties were designed during the Cold War era, and one must admit that the world has changed, the political environment has changed, and the challenges have changed," said Jean du Preez, director of the International Organizations and Nonproliferation Program at the Monterey Institute for International Studies in California. "We now face major challenges by nonstate actors, and so we need to look at ways to adapt these treaties but not to destroy them, and that is, I think, a great concern at the moment."
The Bush administration signaled a new approach earlier this year by building support for a UN Security Council resolution that focuses on preventing the development and trafficking of weapons of mass destruction (WMD) by terrorists and nonstate actors.
Kerry has called for substantial changes in U.S. nonproliferation policy. Foremost, he says, would be the acceleration of programs to secure nuclear materials in the former Soviet Union. He has also indicated he would seek ratification of the Comprehensive Test Ban Treaty and restart negotiations on the protocol to the Biological Weapons Convention.
Kerry and Bush present distinctly different options for negotiating a solution to the North Korean nuclear crisis.
Kerry wants to embark on bilateral talks with Pyongyang, putting all issues on the table. Bush is committed to continuing six-party talks and says Kerry's proposal would undermine those efforts.
Kerry has also faulted Bush for his handling of Iran's nuclear ambitions, but the two candidates' positions differ only slightly. Both support the involvement of Britain, France, and Germany and favor moving the matter to the UN Security Council as the UN's nuclear agency continues to report lack of cooperation from Iran.
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