This article evaluates the Treaty on establishing the European Stability Mechanism (ESM) and the Treaty on Stability, Coordination and Governance in the Economic and Monetary Union (TSCG) from the perspective of protection of the integrity and unity of the European integration process. It is argued that the objectives of those two Treaties could have been pursued within the EU legal order under the pre-existing legal framework. For the ESM, the analysis highlights the inconsistent behaviour of the Eurozone members, who stipulated an international treaty while revising art.136 TFEU to introduce a specific EU legal basis for the ESM. It is then argued that the ESM could have most probably been established within the Union system even in absence of the revision of the EU Treaties. As for the TSCG, the instruments available for the incorporation of its content into the EU legal order are analysed to assess whether they could have also been used without resorting to an international treaty.