The notion that any foreign government or security group in any foreign country would not allow (or would seek to prevent) the Secret Service members who guard Pres. Bush from accompanying him is reprehensible. If Chile does not apologize profusely and take appropriate actions, there should be repercussions from the fiasco in Santiago where Chilean security sought to prevent the Secret Service detail from accompanying the President to his APEC appearance.
The White House and Congress should issue warnings to all other foreign governments about the seriousness of seeking to prevent Secret Service details from protecting the President and publicly proclaim that any such interference will enable the Presidential detail to take all necessary actions to secure the President himself. This comment on The Powerline Blog encapsulates the situation nicely.