Other experts say that prospectively canceling the exercises serves as a signal to North Korea that the U.S. really does want peace. "This agreement is not the foundation of a grand bargain; it is a screening device," says Todd Sechser, a UVA professor and expert in international security. "By making this reassurance, by suspending military exercises, the U.S. is trying to reassure North Korea that U.S. intentions are not aggressive. Now it's up to North Korea to respond by making substantive concessions on their part."