"The iron dome is funded and built with American hardware"

this is partly correct, as obama matched the billions of dollars israel spent on the iron dome.

"If the US disassembled it..."

the US has no right or obligation to "disassemble" another countries infrastructure any more than Nigeria has the right to disassemble the French metro; this is a non-starter.

"Israel would be unable to act with impunity towards its neighbors..."

this is entirely incorrect as Israel does not require US funding to maintain the iron dome, their military, or their aggression.

The annual GDP of Israel is something like 600 billion now, taking away the 3 billion the US gives them each year isn't going to make the difference you think it will, even ignoring all of the other countries that fund israel.