It appears that the IBAF tournament for the 15 and under age group that is going to be held in Chihuahua, Mexico on August 16-26 have had a number of teams drop out because of the political instability there. Japan recently dropped out of the tournament joining Australia, Czech Republic, Netherlands and the United States who were the first to withdraw.
A travel warning from the State Department dated February 8, 2012 linked here with excerpt below may have been there motivation: http://travel.state.gov/travel/cis_pa_tw/tw/tw_5665.html
Chihuahua: Juarez and Chihuahua are the major cities/travel destinations in Chihuahua -see map (PDF, 286 kb) to identify their exact locations: You should defer non-essential travel to the state of Chihuahua. The situation in the state of Chihuahua, specifically Ciudad Juarez, is of special concern. Ciudad Juarez has one of the highest murder rates in Mexico. The Mexican government reports that more than 3,100 people were killed in Ciudad Juarez in 2010 and 1,933 were killed in 2011. Three persons associated with the Consulate General were murdered in March 2010. The state of Chihuahua is normally entered through Columbus, NM, and the El Paso, Fabens and Fort Hancock, TX, ports-of-entry. There have been incidents of narcotics-related violence in the vicinity of the Copper Canyon in Chihuahua.
Two more articles to read concerning the political issue there.