"More intertwined relationships" may also become inconvenient shackles, especially when are used as political leverage (look at Russia with its exports of natural gas in Europe, or at the economic sanctions against Iran). Heck, look at history - given the right condition, an economical relationship by itself can start a war if it cease, becomes abusive, or is altered in some inconvenient way! And as power balance is in continuous change, so are the economical relations shadowed by it.
