The Obama administration remains silent Sunday, more than 24 hours after Iran's supreme leader Ayatollah Ali Khamenei published a humiliating and intimidating graphic on his Twitter feed, showing a silhouette of what appears to be US President Barack Obama pointing a gun to his own head.
The combined texts of the tweet and graphic read: “US president has said he could knock out Iran’s military. We welcome no war, nor do we initiate any war, but… if any war happens, the one who will emerge loser will be the aggressive and criminal US…”
The tweet indicates that Iran is continuing the intimidating psychological warfare against the United States that typified the negotiation process that led to an agreement to gradually allow Iran to develop nuclear weapons. Reports from the negotiations told of explosive outbursts by the Iranian negotiators against the US team.
Britain, meanwhile, lifted an official warning against all but essential travel to Iran on Saturday, citing "decreased hostility" in the wake of the nuclear deal.
Almost all of Iran is now marked green in the government's foreign travel advisory, while only border areas with Iraq, Pakistan and Afghanistan are still marked red, in a warning against all travel.
In a statement, the Foreign and Commonwealth Office said that British nationals should still carefully consider the risks of travelling to Iran, but that the situation had changed under the government of President Hassan Rouhani.
"Our policy is to recommend against travel to an area when we judge that the risk is unacceptably high," Foreign Secretary Philip Hammond said in a statement. "We consider that continues to be the case for specific areas of Iran, notably along Iran's borders with Iraq, Afghanistan and Pakistan. But we believe that in other areas of Iran the risk to British nationals has changed, in part due to decreasing hostility under President Rouhani's government."
The British government has said it hopes to reopen its embassy in Tehran by the end of this year. It was closed in 2011 after being stormed by protesters.