In addition to facilitating applied tariff reductions, GATT`s contribution to trade liberalization includes “the commitment of extended-term tariff reductions (which became more sustainable in 1955), the definition of universality of non-discrimination through the treatment of the most favoured nation (MFN) and the status of domestic treatment, ensuring greater transparency in trade policies and creating a forum for negotiations and the peaceful settlement of bilateral disputes. All of these have helped to streamline trade policy and reduce trade barriers and political uncertainty.  The Kennedy Round took place from 1962 to 1967. $40 billion in tariffs have been eliminated or reduced. However, their main achievement was the adoption of Part IV of the GATT, which freed them from the corresponding reciprocity with developed countries in trade negotiations. In the view of many developing countries, this was a direct consequence of UNCTAD I`s request for a better trade agreement for them. The fourth round returned to Geneva in 1955 and lasted until May 1956. 26 countries participated in the cycle. $2.5 billion in tariffs have been eliminated or reduced.
THE GATT and its successor, the WTO, have succeeded in reducing tariffs. Average tariff levels for large GATT participants were about 22% in 1947, but were 5% after the Uruguay Round of 1999.  Experts attribute some of these tariff changes to the GATT and the WTO.    The fifth cycle took place again in Geneva and lasted from 1960 to 1962. The discussions were named after U.S. Treasury Secretary and former Undersecretary of State Douglas Dillon, who first proposed the talks. Twenty-six countries participated in the cycle. In addition to reducing tariffs by more than $4.9 billion, it has also led to discussions on the creation of the European Economic Community (EEC). Among the original GATT members, Syria, Lebanon and the LICO Yugoslavia have not re-joined the WTO.
Given that Yugoslavia (renamed in Serbia and Montenegro and later two shared accession negotiations) is not recognised as a direct successor to the SFRY; Therefore, its application is considered new (non-GATT). On 4 May 2010, the WTO General Council decided to set up a working group to review Syria`s application for WTO membership.   The WTO parties terminated the 1947 GATT formal agreement on 31 December 1995. Montenegro became a member in 2012, while Serbia is in the decision-making phase and is expected to become a member of the WTO in the future.