The tenor of the exchanges has been sharp and suggestive of the deep divides between the two men's positions.
During a recent debate, Kerry accused Bush of straying from the war on terrorism to invade Iraq: "And if we'd used smart diplomacy, we could have saved $200 billion and an invasion of Iraq, and right now Osama bin Laden might be in jail or dead. That's the war against terror."
Here is Bush describing Kerry during the same debate: "I don't think my opponent has got the right view about the world to make us safe. I really don't. First of all, I don't think he can succeed in Iraq, and if Iraq were to fail, it'd be a haven for terrorists and there'd be money and the world would be much more dangerous. I don't see how you can win in Iraq if you don't believe we should be there in the first place."
But if the two candidates strongly differ over how well the United States has pursued the war on terrorism up to now, it is often hard to see great differences in their strategies for the future.
Bush says he will keep U.S. troops in Iraq as long as it takes to stabilize the country under a strong, popularly supported government. He also says he wants to increase international participation in securing and rebuilding Iraq.
While he has called Bush's invasion of Iraq a "colossal mistake," Kerry also says U.S. troops have no choice now but to stay in the country to stabilize it. He also urges sharing the financial and military burdens as quickly as possible with other nations. But like Bush, he has fixed no date to when America's military forces might leave Iraq and says such a timetable must be determined by events.
Mustafa Alani, a security expert at the Dubai-based Gulf Research Center, said that leaves many in the region wondering how to distinguish between the positions of the two men: "Certainly, the impact of the new election on Iraq will be felt more than other issues in the Arab world. They think Mr. Bush is committed publicly now [in Iraq], and they think that the character of Mr. Bush [is such] that he will try to maintain the forces in Iraq because this is his prestige. So they think that he will have more commitment to build a stable Iraq than Mr. Kerry."
Alani said the question of how long America will stay in Iraq is paramount in the Persian Gulf because of fears that an insufficiently stabilized Iraq could pose security problems for the region.
Another focus of U.S. foreign policy over the next four years will be Iran. But here, too, it is not always easy to figure out how the two candidates differ.
During his four years in office, Bush has sought to continue the long-standing U.S. policy of isolating Iran, which dates to 1979, when U.S. diplomats in Tehran were taken hostage immediately after the Islamic Revolution.
Kerry has given no public indications that he would break with that policy. But his vice presidential running mate, Senator John Edwards, said in September that a Kerry administration would allow Tehran to keep its nuclear power plants if Iran gave up its efforts to manufacture its own nuclear fuel. Nuclear fuel can be used either in commercial reactors or for making nuclear bombs.
Edwards said a rejection by Tehran of this "great bargain" would make it easier for Washington to enlist European powers in imposing strict international sanctions on Iran.
However, it is unclear how this strategy differs from new initiatives by the Bush administration. Senior administration officials met in mid-October with counterparts from the Group of Eight (G-8) industrialized countries to hear proposals from Britain, France, and Germany to present Iran with a "carrot-or-stick" deal, much like Kerry's. The Bush administration stopped short of saying whether it supports the initiative, but said the three European powers would make the offer to Tehran this week, implying Washington's acceptance.
RFE/RL regional specialist William Samii said such developments make it difficult to know how future Bush or Kerry administrations might differ in their approaches. He said the most interested observers -- Iranian officials -- have little to go on other than the record of the Bush administration compared to that of its predecessor, the Democratic administration of former President Bill Clinton.
"They are already aware of the fact that the current Bush administration is not positively disposed towards the Iranian government," Samii said. "So they may well favor what the Kerry administration might provide. Tehran has been viewed through a less hostile lens by Democratic administrations than it has by Republican administrations."
The Clinton administration maintained U.S. sanctions against Iran but called on Tehran to work with Washington on a "road map" toward opening a dialogue about their differences.
No such dialogue took place, however, as both sides set tough preconditions and Supreme Leader Ayatollah Ali Khamenei finally ruled out any new initiatives by Iran.
On Afghanistan, both Bush and Kerry say they are committed to maintaining a U.S. military presence in the country until the Afghan government can guarantee security and stability.
Both candidates say they are determined to prevent any return of the Taliban or Al-Qaeda to Afghanistan and have welcomed NATO's role in maintaining a peacekeeping force there.
Similarly, both candidates support multinational efforts to build democracy in much of the Muslim world through the G-8 backed Partnership for Progress and a Common Future, often referred to as the Greater Middle East Initiative.
And both Bush and Kerry have called for the United States to take new steps to develop energy alternatives to Middle East oil to ensure America is less dependent on foreign powers.
However, some differences have emerged in positions toward individual states in the Middle East.
Kerry has criticized the Saudi Arabian government by saying it has not done enough to crack down on terrorist financing. By contrast, the Bush administration has praised Riyadh for its cooperation in the war on terrorism.
On Israel, both candidates say they are committed to ensuring the independence and survival of the Jewish state. Bush endorses a two-state solution but has not pressed as hard for negotiations as Clinton did. Kerry has argued that Israel must accept the eventual formation of a Palestinian state and negotiate to make that happen.
"U.S.: Election Seen As Multilateralism Versus Unilateralism, But Rhetoric Clouds Reality (Part 1)"
"U.S.: Could Kerry Victory In Election Further Complicate Relations With Europe? (Part 2)"