Здесь говорится, что они принимали участие в учениях уже несколько раз, начиная с 1998.
Military Co-operation
In the summer of 1998, Estonia’s Defence Minister Andrus Öövel visited China at the invitation of China’s Defence Minister Chi Haotian. During his visit, Öövel also met with Vice-President of China Hu Jintao. In August 1998, the first group of Chinese military officers took part in the annual Erna military reconnaissance competition. Further groups from China have successfully participated in subsequent competitions over the years. In 2002, the Chinese placed first and second in the competition.