Yeah, pretty much every time Peter faced total defeat it was because he got over-excited about grabbing a new port. The Great Northern War, which ended well, AFTER 25 years of combat and almost total annihilation, was largely a port war. The 1710 Russo-Turkish War, which ended in disaster, was a war to protect previously stolen ports that ended up in losing him those very ports.

And St. Petersburg DOES catch on fire or flood rather a lot....

- Count Dolby von Luckner