Tussles between US legislators and their president over who has ultimate control over US foreign policy have been leitmotifs of many administrations. And there is no straightforward answer. This month, however, Republicans took the conflict to a new level with the unprecedented bypassing of the president in inviting Israeli Prime Minister Binyamin Netanyahu to address Congress, and with the letter from 47 senators to Iran to warn it that any treaty with President Obama could be repudiated by his successor.
Presidents have gone to war without congressional sanction by defining their military adventures as other than war – Obama is currently seeking a merely symbolic consent for his air war against Isis. Presidents have varied and vetoed sanctions imposed by Congress, and they have circumvented close congressional supervision in trade talks by getting “fast-track” – all-or-nothing – negotiating mandates. And, while the constitution requires congressional approval for treaties, some 94 per cent of pacts agreed between the US and other states since the 1930s have been “executive agreements” rather than treaties.
But a couple of political conventions, not binding but clearly understood by all, have served Congress and the presidency well over time: firstly, that although a president can’t be bound by predecessors’ acts, it makes no sense for the conduct of his own diplomacy if he tears up treaties agreed by that predecessor. No-one would sign an agreement with the US if they understood them to be so conditional. Secondly, that the direct conduct of negotiations with other states is a presidential prerogative, whatever the mechanism for approving the outcome. The alternative is mixed messages.
Republicans have run a coach and horses through both conventions with what the New York Times has described as their "disgraceful and irresponsible letter". Even their party's former presidential candidate and foreign policy statesman Senator John McCain has admitted that "maybe that wasn't exactly the best way to do that." Indeed. As Kissinger once asked of Europe, "who does one call if one wants to call the US?"