In a surprise assault, the Pacific Front has commenced an invasion on Vladivostok. With China being too slow to react, the Russians are now forced to defend their motherland with what little forces they have on the eastern coast. - Mission description
While the war in the United States continued, an emergency had come up from the Motherland. The Pacific Front have joined the war and are now invading Russia's poorly defended Far-east territory. To make matters worse is that their allies, the Chinese, didn't respond and merely ignored the situation. Soviet Command had their hands tied due to the majority of their forces being in United States and within the borders of Europe as well as in the Middle East.
With time being short, the Soviet General left the United States and headed back to the Motherland to muster a defense in Vladivostok. Another warning to him by the Politburo is that the Far East of Russia...was never strongly communist. Hence, he must expect some sort of "defectors" and White Russian resistance.
Although our initial losses were substantial, your defense has kept the Allied fleet at bay, buying more time for our comrades on American soil to consolidate their positions. We must make haste to bring the US under our control before another strike occurs. - Battlefield report
With the Pacific Front invasion thwarted, the General's defence has kept the Allied fleet at bay, giving the Soviets more time for their troops in America to consolidate their positions. The United States must be conquered before another strike from the Far East happened again.