Pandemic Trilogy: The Pool of Fire by John Christopher, 1968, (2003 copy in hand), 076714004993.
Will has escaped from the City of God and Lead and rejoined his group in the mountains. Part of Will's report included news that the aliens are looking to make all of Earth into an alien hospitable environment and kill all the humans.
Will and Fritz - whose escape from the City was delayed - have reunited in the mountains and are sent to the Middle East as recruiters. After a year of traveling and adventure they return to the mountains as the human resistance group accelerates plans to attack the aliens and their cities. The group ambushes a tripod and capture an alien.
Things happen. People argue. Captured alien is accidentally killed by alcohol. Resistance realizes they can poison the alien water supply with alcohol. Will and resistance leader Julius discuss philosophical issues. Will keeps learning to curb his impulsiveness and quick temper.
More action as the nearby City is attacked and destroyed. Will joins that group and then joins another group voyaging across the Atlantic to attack the last remaining alien city. More stuff. More happening. Personal sacrifice by one character to win the day.
Will attends a convention of leaders from around the world. Leaders get into big arguments and start fighting and Will is very disillusioned.
A fun YA tale but I did start to lose some interest.
Finished sometime in October, 2020?