Obama or McCain? How will America fare under the 44th commander-in-chief?

President Barack Obama

Up to a point he has been a success. As he formally kicks off his 2012 re-election campaign, Barack Obama is easily the most famous man in the world, still an icon of cool, still conveying the promise of better yet to come, even if the feeling persists that he has not fully delivered.

He has pulled most US troops out of Iraq, and not only resisted Israeli pressure to attack Iran but – in the first far-reaching talks between the two countries in more than 30 years – struck an accommodation with the moderate President Ali Larijani in Tehran that has increased stability in Iraq and across the Middle East.

More important, led by the first black President in its history, America has recovered some (though not all) of the reputation and goodwill squandered by George Bush. The country is a serious participant in global talks on climate change. It has placed a new priority on diplomacy. Yet neither, as his Republican critics charged during his first campaign in 2008, has Obama been a pushover for America's foes.

The cynical fear-mongering of the Bush era has gone. Obama has waged a smarter "war on terror", focusing on Afghanistan and Pakistan, where he has carried out his 2007 threat to strike al-Qa'ida and Taliban bases inside Pakistan without waiting for permission from an ambivalent government in Islamabad. But even Obama has not been able to reverse the iron truth of history – that, sooner or later, relative economic decline translates into lesser military diplomatic clout as well.

China's ascent has continued. India and other emerging countries suck ever more jobs from the US, despite further tumbles in the dollar. Worst has been the recession at home, a long but unavoidable detoxification from the financial excesses of the Noughties that largely tied Obama's hands during his first two years in office – usually a President's most productive.

All the above, of course, is merely a best guess, and never has a guess about a future President Obama had less to guide it. Were he to win, he would come to power amid colossal expectations, founded on the flimsiest of evidence. At 47, he would enter the Oval Office six years older than John F Kennedy in 1961. But he has spent barely three years in the US Senate. Kennedy was a senator for eight years and a congressman before that.

For clues, therefore, look to his background. It's not just that he served as a community organiser on Chicago's rough South Side, nor even that he's black. What truly distinguishes Obama is that part of him is not American at all. What other candidate for the presidency has had a foreigner for a father, spent part of his childhood in (whisper it not) a Muslim country, Indonesia, and then moved to Hawaii – as far as you can get from the US without actually leaving it?

This doesn't mean he knows more about the world than John McCain, a man steeped in national security issues for decades. It does, however, mean that, more than McCain (not to mention Bush), he will be able to understand what other countries think about America, and thus be more sensitive to their concerns. An Obama presidency will not sacrifice US national interests, but it may have a different perception of where those interests lie.

Diplomacy will be given greater weight. The State Department will regain foreign policy influence lost to the Pentagon under Bush. Expect the US to work more closely with the UN and other international institutions on issues such as nuclear proliferation, poverty and climate change. Right now, of course, candidate Obama is trying to win an election. Thus he again wears the lapel flagpin to prove his "patriotism". He is lambasting Iran, and paying homage to Israel.

On domestic issues, Obama is as liberal as McCain is conservative. But, with the likely backing of solid Democratic majorities in both Senate and House, he will have a much better shot at implementing his policies than a President McCain. America moved rightward in the Seventies and Eighties, but is moving left now.

A President Obama would drop the Bush tax cuts for the wealthy and increase capital gains tax. He supports abortion rights (opposed by McCain) and gay civil unions. In direct contrast to McCain, he would appoint liberal Supreme Court justices. He would also launch a new drive to secure universal health coverage. If that is to happen, the role of federal government is bound to grow. But that is true for the whole sweep of domestic policy, from education and energy policy to financial regulation. Obama is riding a wave of demand, not for less government, but for government that works.

The challenges for Obama

INEXPERIENCE: Perhaps his greatest weakness, and John McCain will be exploiting this. If Americans elect Obama, they will be taking a punt on a man with next to no background in national security and precious little in running anything other than a legislator's private office. This makes his choice of VP and national security team very important. Look for wise and fairly hawkish figures who know their way around Washington.

RACE: The great unknown. Obama has proved he can win white as well as black votes. But no one knows how many Americans object to the idea of voting for a black man, as many who do would never admit it to a pollster. If race is still a negative factor, then Obama will lose. Expect Republican strategists to play the race card – with internet whispering campaigns and other such ploys.

HILLARY: Not the woman herself, but the 18 million-plus Clinton voters in the primaries. Obama must unite the party if he is to win. Hillary thus will have a big part in the healing process. But ultimately only he can win back those female and poorer whites who see Obama as elitist and went for his opponent in the primaries.

President John McCain

In 2012 John McCain, the oldest man ever elected to the White House, is seeking re-election. The Middle East is in even deeper turmoil than when he defeated Barack Obama in November 2008. America was drawing down its forces in Iraq, but that process came to a jarring halt in 2010, as cold war with Iran turned hot, driving oil prices through the roof.

On the other hand, the 44th President has unequivocally signed up to fight global warming and has reached a deal with Russia to all but eliminate nuclear weapons. Around the world the US, if no longer seen as a beacon of hope and justice, is less unloved than in the dark age of George Bush.

At home, however, the gulf between the two Americas, liberal and conservative, is almost as wide as when Bush left office in January 2009. The Supreme Court has moved right, with McCain's appointment of two new conservative justices, as he promised in the campaign. As he pledged, he has cut taxes, But he has also slashed spending, hitting poor Americans hardest, just as energy costs surge further.

This, of course, is only a scenario. It is to be treated all the more warily in a multipolar world where US economic and diplomatic clout is proportionately less, and the writ of Washington does not run as far as it did a decade ago – let alone in the Eighties and early Nineties, when Ronald Reagan and George Bush Senior were at the helm, the Soviet empire collapsed, and Saddam was ejected from Kuwait by the broadest alliance of nations in modern history.

A President John McCain is especially hard to predict, given the disparity between the popular image of the man and the reality. As perceived by the public, he is the quintessential maverick, the tell-it-like-it-is straight talker, ready to defy his party on matters of principle. That is why people believe him, almost alone among Republicans, when he claims not to be a slavish follower of Bush. In fact, on many issues, the distance is more apparent than real.

McCain is a conservative, and his vision is of a conservative America. It borrows from Reagan, but also from Bush – a "compassionate conservative" for the purposes of his 2000 election campaign, but who governed from the right more than any Republican since Hoover. In some ways McCain is a throwback to a purer, vanished conservatism, one unembellished by neo-con fantasies. This conservatism balances budgets, frowns on deficits, and – barring events such as 9/11 or Saddam's invasion of a helpless but strategically vital oil-rich neighbour – believes the US should mind its own business.

It is also conservatism in the most basic, literal sense. If elected, McCain would probably be the first "green" President of America. He recognises the threat to the environment. Almost certainly he would sign up for specific global targets on greenhouse gas emissions, promote renewable energy and impose stringent, long-overdue fuel-economy standards on Detroit.

But in other respects he may prove to be the Bush retread Democrats claim he will be. As a senator, McCain staked out a position on Capitol Hill as an opponent of torture and the violation of detainees' basic human rights. In practice, he has gone along with compromises allowing Bush to continue to do as he pleases.

Conceivably, on the "Nixon goes to China" model, he may extricate the US from Iraq. On the other hand, McCain is, if anything, more hawkish than Bush on Iran, with an even stronger trait of impulsiveness. His commitment to Israel is as absolute as Bush's, precluding serious pressure on the Jewish state to end settlements. He promises to reach a major disarmament deal with the Russians. But in the next breath he threatens to throw Moscow out of the G8.

On domestic policy, McCain toes the Republican line. He is a fierce opponent of abortion. He admits knowing little about economics, but he favours prolonging the Bush tax cuts, even for the very wealthy. Most important, he wants more conservative judges on the bench, a step that would seal his legacy for decades.

McCain likes to compare himself to Barry Goldwater, whose Senate seat he took over in 1986. Goldwater is also a patron saint of modern American conservatism.

The challenges for McCain

AGE: At 72, he would be the oldest man ever to become President (Ronald Reagan was 68 when he took office). The latest McCain medical shows him in robust health, though apparently at risk of melanoma skin cancer. But his age is a concern, particularly if he makes clear he intends to seek a second term. Obama aides have already implied he has "lost his bearings" on certain key issues.

BUSH: McCain's toughest problem will be to distance himself from a toxic President of his own party, of whom 70 per cent of Americans disapprove. The Obama campaign is already arguing that a McCain win means a third Bush term. The trouble is, McCain has to retain the 30 per cent of voters who still support Bush.

THE PARTY: He's liked by independents, but conservatives, the bedrock of the Republican Party, are deeply suspicious. He's tried to make peace with the religious right, but to little avail. "I cannot, and will not, vote for John McCain, as a matter of conscience," James Dobson, leader of the Focus on the Family organisation, said in February. Many will follow that lead.

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