Flexible means they think they can roll Obama.
Everybody will roll all over Obama except the God fearing, red blooded, die hard, American Patriot. Obama will make sure he puts us in our place (see fairness doctrine).
Flexible is the problem. Reagan was the greatest negotiator our Nation had seen in some time. The reason of his greatness was he kept what bargaining chips he had and created new bargaining chips when necessary. He also stood his ground when he believed in something like SDI or Pershing missiles in Western Europe and was not flexible when it came to negotiating SDI.
Flexible is not always a virtue. Especially when you are dealing other Nations. Chruchhill said something like, Nations don't have friends, only interests. Being flexible with friends is OK, but there are very, very few that our Nation can call a friend. Russia, Iran, China, North Korea, Venezuela, and other Socialistic/Communist countries are not our friends. These nations only have interest and our best interest is not of their concern.
Obama's naivety is concerning in many ways. Will he sit down unconditionally? Will he negotiate our bargaining chips away with Russia? Will his interest be the interest of capitalism or socialism?