A “cyber” border wall pushed by Democrats opposed to President Trump’s call for a physical barrier is likely to fail in an attack from Iran or other U.S. foe on the nation’s electric grid and be easily overrun should a pandemic strike in Latin America, key national security experts are warning.

As Trump is considering signing a scaled back border wall package in exchange for Democratic demands to keep the government open, new warnings are being raised that an electronic wall won’t work in an emergency at the border.