"God of War" Lei Chenghu was quite right about one thing.
After mankind explored the three-dimensional universe by way of "space jump" and thereby conquered thousands of Sectors and ten times more resource planets, "attack" was always a hundred times simpler than "defense" in any universal war.
Lei Chenghu was not an external enemy. He was an important commander in the Imperium's army and a seasoned general who had fought for two hundred years. Also, it was possible that he had the help of a certain mysterious force from the capital, meaning that he would know the maps, the distribution of troops, and the jump coordinates of various worlds of the Imperium perfectly.
He could choose his target free at will and appear at any space zone unexpectedly.
The defender, on the other hand, could not distribute all the troops to every world and every planet evenly, which would only be divided and conquered by the enemy. They had to focus the troops in certain areas.