Is there a reason world leaders shouldn’t endorse each other?

According to this Guardian story, the Romney campaign isn’t happy about Prime Minister David Cameron bro-ing it up with President Obama last month:

Senior advisers to Mitt Romney have bitterly criticised David Cameron‘s recent White House "love-in" with Barack Obama before Romney’s first visit to London for the opening of the Olympic Games.

Referring to Cameron’s highly flattering toast to Obama during a banquet given in the prime minister’s honour when he visited Washington in March, a senior aide said: "You don’t take sides in an election year".

The aide, who requested anonymity, said Romney and his wife, Ann, would attend the "first day of activities" of the 2012 Games, which open in July. Romney would do "one or two other things" while in London. A meeting with Cameron was not ruled out, but that was "up in the air", the aide said.

Doubts about a possible Downing Street meeting appear to stem in part from surprise and dismay felt in the Romney camp about what it saw as Cameron’s obsequious behaviour at the banquet on 14 March. Cameron’s performance smacked of a "lack of experience" and was seen as "not very skilful", the aide said.

Romney advisers responsible for European policy were said to have been so alarmed that their initial reaction was to complain Cameron had "infringed" the special relationship between the US and Britain.

Cameron was also criticized in the British media as well for appearing to close to Obama and for a toast that seemed to border on an endorsement of the president’s reelection. 

It’s debatable whether Cameron’s actions really constituted taking sides, but there seems to be a lot of that going around this year. Cameron and Angela Merkel have both given the cold-shoulder to likely future French president Francois Hollande. Nicolas Sarkozy has essentially endorsed Obama.  Obama seemed to return the favor by allowing a few minutes of banter with Sarkozy during a video conference to be broadcast on French television. 

The taboo of commenting on a fellow world leader’s election chances does seem a little silly at times. For instance, it’s seems pretty obvious that Benjamin Netanyahu would prefer to see his old friend Mitt Romney in the White House next year and center-right European heads of state are obviously not  thrilled at all about working with Hollande. Had Marine Le Pen made it to the second round, the rhetoric would have gotten a lot less subtle. It doesn’t really any more unethical for a foreign leader to state a preference than a domestic politician or business leader.

But it’s still a pretty bad idea. First, voters often don’t respond well to foreign leaders telling them how to vote. (See, Greece.) Second, it doesn’t seem like a good idea to alienate a leader you may very well have to work with if the election doesn’t go your way. In the case of the unnamed Romney advisor, this second reason also applies to candidates whining about foreign leaders.