WASHINGTON - The Pentagon said on Thursday that while there were no signs the Syrian government was preparing to launch a chemical weapons attack, they still retained the ability to launch limited attacks in the future."They do retain a residual capability. It is probably spread throughout the country at a variety of sites," said Lieutenant General Kenneth McKenzie, joint staff director."They will have the ability to conduct limited attacks in the future, I would not rule that out. However, as they contemplate the dynamics of conducting those attacks, they have got to look over their shoulder and be worried that we're looking at them and we'll have the ability to strike them again, should it be necessary," McKenzie added.