CAMBRIDGE, United States — US Secretary of State Marco Rubio on Tuesday ordered a suspension of student visa processing in the latest swipe at foreign students in the country. The White House is cracking down on foreign students at US universities, revoking visas and deporting those involved in protests against the war in Gaza, accusing them of supporting Palestinian militant group Hamas. Rubio earlier rescinded hundreds of visas and President Donald Trump's administration moved to bar Harvard University from admitting non-Americans. A cable signed by Rubio and seen by AFP orders embassies and consulates not to allow "any additional student...