Why is it that US child custody orders always over rules a conflicting child custody order?

Why is it that US child custody orders always over rules a conflicting child custody order of another country if the child is a US citizen or a duel citizen of the US & Germany? The child is in Germany with her mother and is very happy living there with her mother according to the US embassy. The US child child custody was entered first, but is not legal binding outside the US according to the US Department of State. The German child custody order was entered in Germany after the US child custody order was entered and this is legally binding in Germany. She is born in the USA and was seven years old when her mother took her to Germany.

BECAUSE!!!!! His sister wanted the cinnamon toast!!