The United Socialist Party (USP) was a major centre-left to left-wing Kaskivian political party.
The historic, 80-year legacy of the party was violently destroyed during the catastrophic leadership of Bettino Lanzone (1987–1995). Rather than fighting the crony capitalism of the 1980s gas boom, Lanzone eagerly participated in it. His tenure was defined by staggering, systemic embezzlement that shattered the moral credibility of the left. Following a humiliating rout in the 1994 election, the final blow occurred in 1995 when Lanzone was personally arrested and convicted of operating a massive, illegal slush fund out of the party headquarters. His imprisonment plunged the USP into five years of leaderless, chaotic limbo until it was mercifully dissolved by Simeone Silla in 2000.