For once, it is difficult to disagree with Donald Trump. “I’m surprised at how badly [Brexit] has all gone from the standpoint of a negotiation,” he told a press conference with Leo

Varadkar, the Irish Taoiseach, last week. He warned against a second referendum, which he said would be “very unfair” on the 52 per cent who had voted for Brexit. “Frankly, I hate to see

[Britain] being ripped apart now.” Not for the first time, the President criticised Theresa May’s Brexit strategy, pointing out that she had refused to listen to his advice during his visit

to London last year. But what was that advice? We don’t know exactly what Trump told the Prime Minister behind closed doors. But we do know that Theresa May subsequently told Andrew Marr:

apparently she was “surprised”. Yet she has no choice but to endure it. Does she ever have a moment’s regret? Does she even wish that she had listened to The Donald? Suing the EU would be

very difficult because there is no obvious court that would have jurisdiction. We may safely assume that the EU’s own court in Luxembourg would not entertain the idea of a member state

taking legal action against Brussels. And it is isn’t clear what would be the grounds for the British lawsuit. But if an independent arbitrator were to rule that the EU had set out to

penalise the British, there might well be a case under international law. The Lisbon Treaty sets out conditions under Article 50 for a member state to leave. If the European Commission were

found to have failed to negotiate fairly and in good faith, then it would be in breach of its treaty obligations. The problem with Trump’s approach is that the EU would almost certainly

refuse to recognise any arbitrator that the British would regard as independent. Litigation may be a useful tactic in business, especially in America, but it seldom works in politics, least

of all at the international level. However, there is a grain of truth in the President’s advice. It is not too late for the British to propose handing over the outstanding issue in the

Withdrawal Agreement, the Irish backstop, to a panel of judges chosen by both sides for arbitration and adjudication. The panel would consist of legal authorities with the experience and

expertise to decide whether, for example, the British might find themselves trapped, or whether the Vienna Convention would apply. The backstop has dogged the entire process and it seems to

be impossible to resolve in any other way. If that issue were thereby temporarily set aside, it might be possible to move forward. However, Trump is undoubtedly correct that the strategy the

UK has adopted so far has been seen to fail. So in the next, even more difficult, phase of negotiations, a more robust approach by the British will be required. It is difficult to argue

with those in both the Remain and Leave camps who doubt whether Mrs May is the right person to lead the British side. Whether it would serve the Government well for the Prime Minister to set

a date for her departure this week, however, is more than doubtful. Such authority as she has left depends on keeping open the question of when or even whether she will resign. The moment

that she names a date, her power will drain away. She has indicated that she does not expect to fight the next election, but that promise is based on the assumption that this Parliament runs

its full five-year course until 2022. If a snap election were to become inevitable, for example because the Government had lost a vote of confidence, then we could forget about that

assumption. Mrs May would have to lead her party in such an election. So it is not in the Conservative Party’s interest, let alone the national interest, for the Prime Minister to pre-empt

her own resignation this week. We can safely assume that this will not happen. What she could do, however, is to indicate that a very different negotiating strategy will be adopted in

future, including the possibility of an appeal to arbitration. If the EU were to refuse, it might be possible to make such an appeal anyway— for example, to the World Trade Organisation.

Theresa May could do worse than listen to transatlantic advice. But the best authority on the art of the deal is not President Trump. It is President Roosevelt — Teddy, not Franklin. “Speak

softly and carry a big stick.”