Arrested like in terms of our laws recognizing that he has been arrested and detained? I would say no. As far as any other country's laws I suppose they could try to do whatever they wanted. But I doubt any country would be able to take him into custody given the amount of secret service detail with plans for just such an event. And I can think of no better way of getting thousands of cruise missiles and a close up look at the US Air Force than to try such a stunt. The moment the President is back in the country safe, they better be in a deep bunker somewhere because it's about to look like a fourth of July celebration the offending country has never seen.