In September 2011, the Commission proposed an amendment to the SBC and called for greater “EU-based governance” to assess the implementation of the Schengen rules. The Commission has proposed that Commission experts make announced or unannounced visits to border crossing points to assess the implementation of the Schengen rules. Therefore, the reintroduction of border controls would be decided at EU level and not at Member State level.  On 7 June 2012, the Ministers of the Interior reached an agreement that gave national governments the right to re-establish internal border controls in the event of an unforeseen emergency, without the agreement of the Commission or Parliament.   Id. art. 2, par. 5, letter a), b. The free movement of persons is extended to citizens of the European Economic Area (EEA) on the basis of an agreement with Norway, Iceland and Lichtenstein, as well as to Swiss citizens.
The Treaty of Amsterdam, signed in 1997, officially integrated Schengen into the Framework of the European Union as a Schengen acquis. The Schengen acquis includes the 1985 Schengen Agreement, the 1990 Schengen Agreement, as well as various decisions and agreements adopted during the implementation of Schengen. When the Treaty of Amsterdam came into force in 1999, the decision-making power of Schengen was submitted to the EU Council of Ministers. The Schengen border code regulates border crossings and facilitates access for those with a legitimate interest in entering the EU. In addition, a specific system of cross-border border crossings has been put in place to facilitate the entry of third-country nationals who are often forced to cross the EU`s external borders. A common visa policy makes it even easier for legal visitors to enter the EU. In 1990, the agreement was supplemented by the Schengen Agreement, which proposed the total abolition of systematic internal border controls and a common visa policy. The Schengen area operates very similarly to a single state for international travel purposes, with external border controls for incoming travellers and common visas, but without internal border controls. It currently consists of 26 European countries, with a population of more than 400 million and an area of 4,312,099 square kilometres.  In December 1996, two non-EU states, Norway and Iceland, signed an association agreement with the countries that signed the Schengen accession agreement.
Although this agreement never entered into force, the two countries were part of the Schengen area following similar agreements with the EU.  The Schengen Agreement itself was not signed by non-EU states.  In 2009, Switzerland officially concluded its accession to the Schengen area by adopting an association agreement by referendum in 2005.  The convention contained several provisions relating to visa policy and borders. With regard to short-term visas (less than 90 days), the agreement stressed the need for a common policy on the movement of persons and the modalities for issuing visas, as well as provisions for uniform visas for travel throughout the Schengen area. Longer-term visas (over 90 days) should continue to fall under national jurisdiction. Although there are no internal border controls, external borders should be subject to uniform principles, but should remain within the scope of national jurisdictions and legislation.