Dear evil engineer: Could I hold Vatican City hostage with an antimatter weapon?

Dear Evil Engineer, Since childhood, I've wanted to become an absolute monarch like the villains I looked to as role models: Ivan the Terrible, Gaius Caligula, Vlad the Impaler and Emperor Palpatine. There are few absolute monarchies remaining in the world, and once you exclude those based in countries too hot for one accustomed to British weather, only Eswatini and Vatican City are left. I thought Eswatini was an app, so Vatican City it is. It's small, yes, but it's covered in gold, has an unbeatable Raphaels per capita ratio, and I already speak a little Italian. Dove sono i bagni?