There has been a marked change in tone towards communist Cuba under President Obama with an emphasis on engagement rather than confrontation. On the campaign trail, Barack Obama had pledged to lift the Bush-era restrictions on Cuban Americans visiting relatives on the island and sending remittances home. That promise has been fulfilled. It is a small largely symbolic step – the decades-old trade embargo remains firmly in place – but the move was warmly welcomed by most Cubans and, initially at least, raised expectations that an end to this leftover conflict from the Cold War could be in sight. President Raul Castro responded by saying he was willing to discuss “everything”, including human rights, political prisoners and freedom of the press. There was a positive response from Washington. But the island’s former leader, the veteran revolutionary Fidel Castro, then wrote an apparently contradictory article saying that President Obama had misinterpreted his younger brother’s remarks. Barack Obama’s initial moves were by presidential decree. Any substantive changes to the trade embargo will need Congressional approval. More immediate steps could include confidence-building measures such as working together on issues such as drug trafficking and migration Washington though is urging caution, warning that significant changes will take time.

The Obama team may be pleased to know that after 100 days the new president has lost none of his massive popularity in the country that used to be America’s fiercest European critic. To say that he has not put a foot wrong in the job would be overstating it, because the French have not followed the ins and outs of beltway policy-making that closely. But what they get is the big picture. They see the planned closure of Guantanamo; the admission of torture on terrorism suspects; the resumption of stem cell research. They read in their papers of the overtures to Iran; the confirmation of military withdrawal from Iraq; the massive spending programme to get through the economic recession. All of these emblematic initiatives tend to confirm the message that France wants to hear: that Barack Obama is indeed the anti-Bush. From the outset the French have dared to hope that the new president will mark so clean a break from his predecessor that their own recent record of anti-Americanism will be shown restrospectively to have been justified. So far he has not disappointed.

At a popular level, President Obama has completely changed attitudes towards the United States. His recent visit to Britain for the G20 meeting showed that vividly. Most ordinary Brits seem thankful that what they saw as the confrontational stand of the Bush administration in world affairs has gone. At a government level, the attitude is less clear-cut. The British government actively supported President Bush’s invasion of Iraq and although it distanced itself from some of the Bush policies – for example, Guantanamo Bay and the use of techniques Britain viewed as torture – it was far closer to the Bush administration than many other governments and many of the British people. However, privately, there are no regrets for George W Bush. Having the US back seriously engaged in multilateral diplomacy – over Iran, global warming, nuclear weapons reductions with Russia, among other issues – is very much welcomed. If there are concerns, they are about whether President Obama can deliver. As for the so-called “special relationship”, this gets less special over the years, but the US will certainly not kick sand in British faces right now, given the British commitment to the war in Afghanistan.

Russia’s political establishment is very confused by President Obama. Firstly, not many of them thought he would get elected. America is, after all, a neo-imperialist, former slave-owning society, run by a white Anglo-Saxon protestant elite – or so they thought. Since his inauguration, the surprises have kept coming. First was Hillary Clinton’s famous pressing of the reset button. Then President Obama announced his intention to sign a new deal on slashing US and Russian nuclear weapons by the end of this year. The negotiations have already begun. By Russian standards this is all breathtakingly fast. According to experts here there is, as yet, no consensus on what Obama means for Russia. Some see him as a real opportunity to forge a better, more constructive relationship with America. Others see him as a challenge for Russia. A big part of that is his huge worldwide popularity. Russia can no longer rely on strong anti-American feeling to help further its own goals in (for example) the Middle East and South America. Even at home, Mr Obama presents something of a challenge to the establishment. Up to now, the Kremlin has been able to blame America for the economic crisis that is now hitting Russia so hard. With George Bush in the White House it was an easy sell. But even in Russia the young, handsome and charismatic president is very popular. He’s much more difficult for the Kremlin to cast as a bogeyman.

Most Palestinians seem to acknowledge some change in American tone since Barack Obama took office. But they have also seen no positive change in the “facts on the ground”. That is particularly true of Israel’s decades-old policy of expanding Jewish settlements on occupied Palestinian land, in violation of international law. On her recent visit to Ramallah, US Secretary of State, Hillary Clinton described the continuing settlement growth only as “unhelpful.” Politicians here were critical. They would have preferred “illegal” or “unjust,” or better still, the threat of sanctions against Israel. However, they have been pleased with the US assertion that a solution to the conflict which results in the creation of a Palestinian state is the “only solution.” Even Hamas has given President Obama credit for a “new language” in relation to the Middle East. It has expressed hope that the US policy of not dealing with the Islamist faction may change.

“The Israelis are extremely apprehensive,” said one top-level Western diplomat, earlier this month. “They see these reports pop up in the press that the (Obama) administration is going to be tough. And they wonder what that means.” Binyamin Netanyahu, the new Israeli Prime Minister, in charge of a government itself only four weeks old, has tried to buy himself some time, by ordering a full internal review of peace negotiations. The deadline for the review’s conclusions is his trip to Washington in the second half of May. Already, though, there has been some softening of the Israeli government’s language. The largely right-wing coalition has been cold to the idea of full Palestinian statehood – a direct clash with President Obama’s vision. Recently, though, the Israeli foreign ministry has been keen to stress its support for the Road Map of 2003, which foresees, in the end, a Palestinian state alongside Israel. Similarly, George Mitchell, the new US envoy to the region, and the quiet man of diplomacy, appears to have cocked an eyebrow when Mr Netanyahu suggested that, to resume political negotiations, the Palestinians would first need to acknowledge Israel as the Jewish state. That precondition seems, since, to have evaporated. The Israelis know that, although they can point to continued Palestinian inadequacies and divisions, there will come a moment when President Obama may ask tough questions of them: about, for example, settlement expansion in the West Bank and house demolitions in occupied East Jerusalem. “There will also be a time,” says the senior western diplomat, “when America will move from Israel’s best friend to mediator. And then Israel has to realise that America is still its best friend.”

America may have had a new president for 100 days, but many of those who rule Iran still seem to pine for the certainties of life under George W Bush. The Iranian government has appeared divided and hesitant about how to respond to the “hand of friendship” offered by President Obama. For the most part, Iran’s leadership has decided to ignore it, calling for “real change” from the new administration, while offering little in return. At a government approved demonstration in Tehran recently, the first chants of “Death to Obama!” were heard, alongside the ever-present cry of “Death to America!” As for the Iranian people, unlike their government, many are curious and optimistic about Barack Obama. But their leaders don’t seem to be listening. Iran has accepted the offer of talks on the biggest issue dividing the two countries, Iran’s nuclear programme. But President Ahmadinejad has made it clear there’s no question of Iran compromising. With Iran now facing its own presidential election on 12 June, the diplomacy has barely started. But dealing with Iran promises to be one of the biggest challenges facing President Obama, as it was for his predecessor.

Kenya was euphoric when Barack Obama was elected. People here saw him as one of their own – because his father was Kenyan – and that has not changed. There is also still a feeling that this charismatic leader is projecting a completely new image of America, and can help improve America’s relations with the rest of the world. When Obama was seeking support for his $1trn stimulus package, and he visited some of the US’s dilapidated roads and bridges, I heard someone say: “He has brought African politics to the US.” It’s not often you see the American president talking about development projects, and infrastructure improvements, like you might here in Africa. Kenyans are still hoping that Kenya will be the first African country Obama will visit, but have perhaps become more realistic about benefits he can deliver. This country will not get special treatment – but neither will be it forgotten in Washington. Some people hope that Obama will push Kenyan leaders to get serious about political and economic reforms.

The first seven or eight minutes of the Obama-China relationship went quite well. Then it hit trouble. Chinese viewers were happily watching coverage of Mr Obama’s inaugural speech live on state TV, when the new president got to this passage: “Recall that earlier generations faced down fascism and communism not just with missiles and tanks, but with sturdy alliances and enduring convictions.” At this point, Chinese state TV cut away from Mr Obama’s speech. Broadcasting strident criticisms of communism is not the kind of thing that a communist government likes to do. Since those first few minutes, the Obama-China relationship has settled into a pattern of engagement and occasional conflict. The Obama administration has asked for China’s help on North Korea, the global financial crisis, and also climate change. But in March, ships from the US and China clashed in the South China Sea. This was the most serious military confrontation between the two countries for almost a decade. Barack Obama is the commander in chief of the world’s only global military power. China has ambitions to project its military power well beyond its borders. Managing this changing military relationship will take a lot of work.