It went against long-standing diplomatic protocol for an ally to speak on behalf of the U.S. President.

由盟友代表美国总统发言违反了美国长期以来的外交礼节。

" Permission to do a thing, ma'am, slightly outside diplomatic protocol."

“女士，允许做一件事，但稍微超出了外交礼节。”

The Foreign Office here says it's seeking clarification on the current status of Myanmar's ambassador in London in line with diplomatic protocol.

当地外交办公室表示，他们正根据外交规定验证现任缅甸驻伦敦大使的合法性。

His or her job is to give advice to the president and the secretary of state about certain diplomatic protocols – that is, how things are supposed to be done in dealing with other countries.

他或她的工作是就某些外交礼仪向总统和国务卿提供建议——也就是说，在与其他国家打交道时应该如何做。