President Obama's time in office has not been defined by terrorism as President George W. Bush's was. Yet incidents like the one in Boston have been a regular, painful through line of his presidency.
When a new administration walks into the White House, nobody provides a handbook on how to respond to a terrorist attack. So the Obama administration has been on a steady learning curve.
When an underwear bomber tried to bring down an airplane on Christmas Day 2009, the White House was basically silent for two days.