Hedging Their Bets?

This wasn't on my Radar Screen until now, but seems that Tokyo and Rio aren't just content making a play for the 2016 Summer Games; as China Daily reports , Beijing has made its own pitch to host the 2015 Athletics World Championships. Should Chicago enter the fray; or are the Japanese and Brazilian cities' own interest in "Athletics Worlds" a sign that they might harbor doubts as to the relative strength of their respective bids for the 2016 Olympics?