Gents,
I agree that the Nazis would have backed down. Like the threats to the Czechs in 1938, re-occupying the Ruhr was one of those operations in which the Heer was waiting for the Nazis to fail. A French show of force in the Ruhr in 1936 could cause a coup by Germany's armed forces well before any loss of public support drove them from office.
Going off on a tangent here, what might happen in SteveW's TL Petain in 1934 - A Sinister France could be very interesting. Petain has set-up a clerical-fascist government in France that still maintains great enmity towards Germany. If Hitler reoccupies the Ruhr while clerical-fascist Petain rules in France, there will be much more than two French battalions marching over the Rhine.
World opinion would support France at first, after she's merely upholding the Treaty of Versailles. However, what would occur if (or when) Petain decides to push Germany further?
Bill