Smith's return to the U.S. on July 22, 1983, was celebrated by the people of Maine with roses, a red carpet, and a limousine and her popularity continued to grow in her native country. Some critics at the time remained skeptical, believing Smith was unwittingly serving as an instrument of Soviet propaganda. In December 1983, continuing in her role as "America's Youngest Ambassador", she was invited to Japan, where she met with the Prime Minister Yasuhiro Nakasone and attended the Children's International Symposium in Kobe. In her speech at the symposium, she suggested that Soviet and American leaders exchange granddaughters for two weeks every year, arguing that a president "wouldn't want to send a bomb to a country his granddaughter would be visiting". Her trip inspired other exchanges of child goodwill ambassadors, including a visit by the eleven-year-old Soviet child Katya Lycheva to the United States. Later, Smith wrote a book called "Journey to the Soviet Union" whose cover shows her at Artek, her favorite part of the Soviet trip.