premise: Prime Minister Vo Van Kiet has issued a directive calling on all levels of government to tighten vigilance against revealing state secrets, reports said Saturday.
  According to the April 24 directive, portions of which were published in all daily Vietnamese-language newspapers, "the situation of revealing state secrets in a number of offices and localities is still serious," the Communist party's official mouthpiece Nhan Dan said.
  The paper quoted the government as saying that since 1991 when the ordinance on Protection of State Secrets was issued much progress had been made, but there were "cases of abusing regulations on state secret protection."
  Vietnam has nebulous laws on state security and press freedom that give the government a free hand in restricting the media. The laws allow for criminal prosecution and harsh prison terms for those who reveal state secrets or damage national interests.
   What event caused much progress to be made?
hypothesis: ordinance on Protection of State Secrets was issued