Brazil.  Misspelled the president's name, and put his legal name in parentheses as though it a nickname.

China.  He sent warships into the South China Sea to attempt to intimidate the Chinese government.

United Kingdom.  He refused to have a joint press conference with the Prime Minister, returned a bust of Winston Churchill, gave them DVD's from the local Walmart as a State gift, and a spokesman said that the UK is just one of another 190 countries and deserves no special treatment.

Russia.  Injected, again, internal politics into foreign relations by insulting the previous administration, and at the same time looking incompetent by giving a mushroom button to the Russian Foreign Minister, claiming that they worked very hard to properly translate the word "reset" but in fact the word on the button is properly translated as "overcharge."  And after the cold war, they seemed to miss the irony of giving the Russians a red mushroom-shaped pushbutton. 

Poland.  Undermined the US-Polish friendship by offering to toss out the Poles' support for the missile defense system in exchange for being friendly with Iran.