Backgrounder: Experts say more should be done to reduce risk on both passenger and freight rail.

After more than three decades of existence, the Group of Eight (G8) is struggling to defend its relevance amid criticism of its limited membership and lack of a compliance mechanism.

A new arms control agreement with Russia has met political opposition in the U.S. Senate, and some analysts believe its fate is tied to the outcome of the 2010 midterm elections. This Backgrounder ex…