On 2006’s Living with War, Neil Young straps on his guitar to protest the United States’ invasion of Iraq. Howled, shouted and pounded out, “Let’s Impeach the President” is a riff-packed indictment of George W. Bush, while the distortion-blasted “Shock and Awe” takes a grisly look at the carnage of war. But Young is ultimately an optimist; punctuated by trumpet cries and sing-along verses, he pledges allegiance to pacifism on the title track with a timeless earnestness.