Wall Street’s biggest banks, whose missteps caused a global financial crisis and economic slowdown two years ago, were more agile when it came to countering the political and regulatory response. The U.S. government, promising to make the system safer, buckled under many of the financial industry’s protests. Lawmakers spurned changes that would wall off deposit-taking banks from riskier trading. They declined to limit the size of lenders or ban any form of derivatives. Higher capital and liquidity requirements agreed to by regulators worldwide have been delayed for years to aid economic recovery. “We continue to listen to the same people whose errors in judgment were central to the problem,” said John Reed, 71, a former co-chief executive officer of Citigroup, who estimated only 25% of needed changes have been enacted.