I would empty the White House and other buildings of all historical items. Then stand back and let them do whatever. Let the city deal with it. If they happen to destroy the capital then .. put it up for bid across the nation and move it to a more suitable location. Rebuild it with today's private sector. Let our nations people and not just these fringe groups deal with the consequences of their actions.

It's beautiful having someone in the Whitehouse that knows the best solutions don't come only from government.