Unwilling to yield to any pressure Greece and Serbia settled their mutual differences and signed a military alliance directed against Bulgaria on 1 May 1913, even before the Treaty of London had been concluded.
Soovimata mistahes survele järele anda, lahendasid Kreeka ja Serbia omavahelised erimeelsused ja sõlmisid 1. mail 1913 Bulgaaria vastu suunatud sõjalise liidu, isegi enne, kui Londoni leping sõlmiti.