The election, then the re-election, of Barack Obama had raised a wind of hope among African-Americans. They wanted to believe that the fight for equality of rights – led by Martin Luther King and others at the end of the 20th century – would see a growth under Obama’s presidency toward a calmer and more reconciled society.

But 53 years after the assassination of President Kennedy, a new drama in Dallas – five policemen killed, seven others wounded – broke, at least for a while, this dream. The murderer, a black former serviceman, acted after the death of two African-Americans killed by the police, one in Baton Rouge, Louisiana, the other one in Saint Paul, Minnesota... At the end of the first week of July, tensions remained high in the United States.

These dramatic sequences illustrate the scale of weaknesses in American society, which Obama’s successive mandates have not filled; a considerable failure of the White House, just like Obama's lost battle against firearms. The president is obviously not the only cause of this failure. In his own way, he, in fact, made a commitment to these topics, but he came up against a wrinkled, seriously communized country. The disproportionate weight of the lobbies and the tensions – omnipresent in certain neighborhoods – prevented difficult advances on two crucial questions: weapons and discrimination.

Barack Obama thus chose to mark the occasion. He shortened his trip to Europe and will return to Dallas at the beginning of the week. But this spiral of violence will force him into a clearer commitment, in spite of a presidential election campaign widely dominated by the populist sheep and the racist splinters of Donald Trump. Peacekeeping in such a context will be a difficult task.