The Russians and Chinese will see the attack coming by their satellites. We will give the Russians and Chinese some advance notice (without the specifics) so they can give a last chance warning to North Korea. Given the unprecedented Russian and Chinese support of the UN resolution, it shows that they really want us to pressure NK, but not attack. So serious US preparation for an attack-- like moving 10,000 plus civilians and military dependent families out of N. Korea, will force Russia and China's hand to either step up pressure and add their voice to warnings to NK or try to stop the attack by installing anti-aircraft and anti-missile defense system in N. Korea. In simulations done for the military war colleges (unclassified), some scenarios R and C install such systems to deter US action but threaten NK with taking them out if R&C does not accept conditions for talks-- a strong way to let NK know they are about to lose their last chance-- a redline to NKfrom R, C and USA.