As an accumulation of national interests, a treaty is a disbanding thing if Member States consider that their national interests are being harmed. Result: a disunion.
Many people, both in the West and in the former socialist countries, display an attitude which I call—somewhat pointedly—“a mentality of Soviet official”. It is a generalized belief: “whatever problem there exists, only the state can solve it.” The state is perceived as a deity, i.e. an omniscient and benevolent being with unlimited resources.