经过了长达三年的等待之后，Green Day于2000年发行了第六张专辑，也是他们在主流唱片公司的第四张专辑《Warning》，这张专辑这张专辑在发行之后以15万6千张的销量名列排行榜的第四位，销量再次突破百万张。 　　By 2000, Green Day had long been spurned as unhip by the fourth-generation punks they popularized, and they didn't seem likely to replicate the MOR success of the fluke smash "Good Riddance (Time of Your Life)." Apparently, the success of that ballad freed the band from any classifications or stigmas, letting them feel like they could do anything they wanted on their fifth album, Warning. They responded by embracing their fondness for pop and making the best damn album they'd ever made. There's a sense of fearlessness on Warning, as if the band didn't care if the album wasn't punk enough, or whether it produced a cross-platform hit. There are no ballads here, actually, and while there are a number of punchy, infectious rockers, the tempo is never recklessly breakneck. Instead, the focus is squarely on the songs, with the instrumentation and arrangements serving their needs. It's easy to say that Green Day have matured with this album, since they've never produced a better, more tuneful set of songs, or tried so many studio tricks and clever arrangements. However, that has the wrong connotation, since "mature" would indicate that Warning is a studious, carefully assembled album that's easier to admire than to love. That's not the case at all.