US President Donald Trump's decision to move the US Embassy in Israel to Jerusalem was an unpleasant surprise for European diplomacy and also confirmation of an alarming trend – the unwillingness of Washington to pay attention to European interests and concerns. For European leaders, the decision raises many questions regarding the Middle East and Europe's security, as well as the future of world order and the cooperation between Europe and the US. The decision is clearly a dangerous one, but it could also be an opportunity. “The EU is not a real factor in the world” acknowledged the German foreign minister last week, who added that “it will have no real influence until it has defined its own European interests clearly, and without this definition of its own interests it simply will not be able to project power” outside Europe. This lack was already a serious issue 20 years ago, and things are getting worse. The US is retreating from many areas and is being replaced by revisionist powers. It is willing to experiment with obviously bad ideas and is unwilling to handle the expected consequences. It has an ever-shrinking stick with which to beat the recalcitrant, and its speeches are getting louder. Even worse, it now seems to be contemptuous of international law. However, the strengthening of international rules and of multilateralism is a major European goal. The last two decades showed the limits of force in international affairs, and the European armies are in any case in bad shape. As a result, a Kantian world of international rules is one of Europe's major goals, both in itself and as a tool for trade and commercial interests. The fact that the US president has joined the list of leaders who blatantly and consistently violate the rules is a worrying development, which is why French President Emmanuel Macron kept on insisting on the legality issue when he “disapproved,” much less than a condemnation, of Trump's decision. German officials have also stressed the importance of international law and expressed concerns for its future. German Chancellor Angela Merkel has said Germany will stick to UN resolutions on Jerusalem. British Prime Minister Theresa May, who also “disagreed” with Trump on his decision, did not mention international law in her statement. However, she also went further than Macron, Merkel and Trump in the substance of what she said by saying that Jerusalem should be the shared capital of the Israeli and Palestinian states. All the main European countries considered Trump's decision to be at least “unhelpful”. Some analysts, for instance the French commentator Jean François Daguzan, said it was a “departure from a consistent joint Western position” without prior notice. Europe considers the Middle East to be the source of two major threats: terrorism and migration. The decision by Trump aggravates the first of these, to say the least. Al-Qaeda is already trying to capitalise on it, and it has launched a media campaign to encourage terrorist attacks. Some experts think some young Palestinians may now opt for jihadist ideologies as a result. Moreover, the decision strengthens the jihadist and Islamist narrative, which says that the conflict between the Israelis and the Palestinians is a religious one and is a latter-day Crusade. This major concern may explain why Macron condemned the attacks against Israelis during his joint press conference with Israeli Prime Minister Benjamin Netanyahu during the latter's visit to Paris last week. He seemed to be indifferent or oblivious to the fact, underlined by French commentator Xavier Guignard, that this strengthened the “double standard” narrative or at least was an unnecessary concession to Israel's views. Migration is now also an obsession in European capitals, and the Europeans have a keen interest in calming the waters in the Middle East to prevent further conflicts and a new flood of refugees. Macron urged Netanyahu to help defuse the tension in the region by “doing something,” perhaps freezing the Israeli colonisation of the West Bank. It is doubtful that he will oblige, however. Gestures could help the Palestinians to return to the negotiating table, but it remains to be seen whether Netanyahu wants to do so. It should also be noted that the Middle East plays an increasingly important role in European domestic politics, due to the increasing Muslim presence in Europe. France, which has the biggest Muslim and Jewish minorities in Europe, is feeling the heat, for instance as a result of the tensions and incidents between young people from the two communities that have taken place in recent years. “Boycott Israel” activism in Europe is also a source of frequent disputes. Last but not least, Germany and Eastern Europe are increasingly worried by Turkey's aggressive behaviour in the region, and to lesser extent by Iran's, and the Trump decision is a gift for these countries. The German foreign minister made a brief allusion to this “challenge” in a speech ten days ago, and Turkish President Recep Tayyip Erdogan has already been making noises as a result of Trump's latest move. Many European leaders, including Macron, have repeated the conventional mantra: a negotiated two-state solution is necessary in Israel/Palestine, and the parties should continue the dialogue to achieve this aim and should refrain from any actions compromising this goal. Before last Sunday's meeting between Netanyahu and Macron, French TV reported that French diplomats were saying that the US had “disqualified” itself as an honest broker in the Israeli-Palestinian conflict and that the decision was a “major opportunity for France to play a more important role provided that EU members support it.” However, during his joint press conference with Netanyahu, Macron ruled out “for now” any French initiative, as he wanted to prevent any multiplication of possibly contradicting efforts. He reiterated his commitment to Israel's security and said the two countries would develop commercial, technological and cultural cooperation. The tone was friendly, and Macron did not contest the Israeli version of events, but Iranian expansionism remains a major problem in the region. Macron probably wants to see whether Trump has a larger plan, as there has been a lot of talk about a new US initiative, and to consult with allies. Many European commentators say the US president thinks he will be able to extract major concessions from the Palestinian leadership and add that in this he is probably wrong. It is possible that the Europeans prefer to wait before undertaking anything new in the region. I confess I had hoped for a French or German statement that at least mentioned the Palestinian right to East Jerusalem. I do not know if this would have been sufficient to defuse the tensions, but it was probably necessary. Of course French and German officials know that Jerusalem is a crucial issue for Israel, and that it will not easily accept Palestinian sovereignty over part of it. I do not know whether their discretion was considered necessary, in case they later decided to take on the US role of brokers in the conflict. But I do think that Macron's press conference with Netanyahu was a major disappointment for the Arab camp. The writer is a professor of international relations at the Collège de France and a visiting professor at Cairo University.