Austria-Hungary: "Serbia!"

Serbia: "what?"

Austria-Hungary: "you slaughtered my archduke! little demon!"

Serbia: "what!? no!"

German Empire: "hmm.... suspicious, let us investigate in your territory"

Austria-Hungary: "yes, let us investigate, and with military troops!"

Serbia: "uh....no"

German Empire and Austria-Hungary in unison: "we declare war on you"

Serbia: "shit..."

Russian Empire (arrives epically): "stop! no one attacks my bitch, I say Serbia, I defend it"

German Empire: "then I declare war on you too"

German Empire looks at France: "and you too, silly France"

France: "damn!"

United Kingdom: "hmm... I should do something..."

Italy: "me too"

Belgium: "this will not end well"

Ottoman Empire: "hey... I still exist"

United States: "HAHA! AMERICA! YES! 2 x 1 MACHINE GUNS AND RIFLES IN CASE SOMEONE NEEDS THEM FOR A WAR! I WILL BECOME A WORLD POWER! FUCK YEAH!"