LVIV, Ukraine (Reuters) – Ukrainian President Volodymyr Zelenskiy on Tuesday stepped up criticism of NATO following Russia’s invasion of his country, questioning the alliance’s commitment to its Article 5 collective defence clause. Zelenskiy said in a video address that Article 5 had never looked “as weak as it is today.” NATO has not sent troops to defend Ukraine, which is not a member of the Western military alliance, and Zelenskiy suggested NATO would react “in the same way” to one of its members being attacked by Russia. NATO leaders have previously dismissed such suggestions. U.S. Secreta…