My son wants to join his friends at a party with alcohol

He's 17 and his buddies are throwing a party this weekend. He swears nothing crazy will happen and that he won't drink. Part of me wants to trust him but another part knows how these things go. How strict should I be? I want to raise a son who makes good choices on his own, not just because dad's watching. Would love some perspective from you guys who've navigated the teen years.