Complex sentence: They plan to launch an offensive against the Skynet base in San Francisco in four days, in response to an intercepted "kill list" created by Skynet with a plan to kill the Resistance's command staff.
Split into simpler sentences: They plan to launch an offensive against the Skynet base in San Francisco in four days. This is in response to an intercepted "kill list" created by Skynet with a plan to kill the Resistance's command staff.