US President Barack Obama said on Thursday during his speech on counterterrorism policy at the US National Defence University. President Obama revealed clearer guidelines for the use of deadly drone strikes. Obama said as the terrorism fight has moved to a new stage, military tactic is legal, or even effective, is not to say it is wise or moral in every instance.  According to the president, terrorism risks have declined, so it is necessary to make some changes in counter-terrorism policies, including closing the Guantanamo Bay detention center where 166 terrorist suspects are detained and brought to trial those with enough evidence.