He doesn't have the authority to pay them anymore.
WWII memorial was built >90% on private funds, and its maintenance is 100% paid by its trust fund
therefore - it costs zero dollars to maintain.
What the hell is there to maintain that is essential to allowing someone to walk up to a marble post and read
There is no staff, only patrol by the park police, which will STILL BE WORKING.
They are spending money to barricade off an exhibit for NOTHING.