As the contact area increases, both summits and valleys can form as contact clusters.
Russia will continue to contribute to the work of both summits.
The outlook is for a continued stalemate in Germany - ratified by the heads of govt. at both summits.
For example, she chose Meseberg, a baroque castle an hour outside Berlin, as a setting for informal talks before both summits.
The agenda for both summits is "sustainable development", a rather woolly notion that is about how to grow in an environmentally friendly way.
Ngigle, who said he and fellow union members wanted to spread their message to those in charge abroad, said he was optimistic about both summits.
Amnesty, Human Rights Watch and refugee charities are among those accusing both summits of being "toothless" and saying that the declaration expected to be ratified by the UN on Monday imposes no obligations on the 193 general assembly nations to resettle refugees.
Both summits will attempt to tackle these challenges.
Both summits also featured several uncomfortable personal moments between the American president and his European counterparts.
