Complex sentence: Both the Czech and Slovak Republics have ratified the Vienna Convention on Succession of States in respect of Treaties, however it was not a factor in the dissolution of Czechoslovakia since it did not enter into force until 1996.
Split into simpler sentences: Both the Czech and Slovak Republics have ratified the Vienna Convention on Succession of States in respect of Treaties. However, it was not a factor in the dissolution of Czechoslovakia since it did not enter into force until 1996.