WASHINGTON, April 29 - The chair of the Senate Foreign Relations Committee on Thursday will call for new efforts to address growing national security concerns over submarine communications cables that handle 99% of international internet traffic."To end undersea sabotage, we need to call it out when it happens and say publicly who did it, if possible," Republican Senator Jim Risch plans to say at a hearing, according to prepared remarks seen by Reuters. "We also need a concerted international effort to improve the resiliency of undersea infrastructure and prevent or mitigate the impact of these attacks when they happen."The committee...