There's also the other famous bit of German diplomatic ineptitude with the Zimmerman Telegram, wherein Zimmerman suggests the ambassador to Mexico suggests the Mexican president to invade America once America declared war on Germany. This despite both Mexico and Germany knowing that Germany absolutely could not follow up on any of its unreliable promises of support and that Mexico was woefully outmatched by the United States, but Zimmerman was still confident the Mexicans would do it anyway.