What does Nose of the camel in the tent mean?
The camel puts its nose inside the tent to seek warmth in the
cold desert night; but it's a folly to think the camel will stop
there. Unless resisted promptly, the whole camel will soon be
inside the tent displacing its human occupiers! The phrase refers
to a small initial step that will almost surely be followed by a
much bigger, potentially disruptive, step to come.