The American president omnipresence in the media and in the social networks has an inconvenient which he seems not to have completely controlled: to attract attention, it is necessary to avoid, as possible, to repeat himself and to announce every time something new. That leads him to take decisions and to pass judgments which are frequently carrying contradictions. The most worrying point is that he doesn’t seem conscious of that when even he falls into a denial. It is this instability of the economic policy and of the American diplomacy which constitutes a threat for financial markets as for ...