President Barack Obama asked Congress on Thursday for $83.4 billion for US military and diplomatic operations in Iraq and Afghanistan, pressing for special troop funding that he opposed two years ago when he was senator and George W. Bush was president. Obama's request, including money to send thousands more troops to Afghanistan, would push the costs of the two wars to almost $1 trillion since the Sept. 11, 2001, terrorist attacks, according to the Congressional Research Service. The additional money would cover operations into the fall. Obama is also requesting $350 million in new Pentagon funding to deal with Mexican drug cartels and conduct other security activities along the US-Mexico border, along with another $400 million to help Pakistan in counterinsurgency efforts along the border with Afghanistan. While the Iraq war by far gets the most money, the request reflects a shift in focus from Iraq to Afghanistan, where severe challenges remain and where the former Soviet Union learned firsthand the difficulties of battling Islamic extremists.