Five things Donald Trump should bear in mind when appointing his new Vatican ambassador

She's probably one of the best connected figure in one of the world’s most complicated and colourful cities, counting George W Bush, Henry Kissinger and Condoleezza Rice among her friends - and her soirees in her villa just outside Rome frequently include leading cardinals, diplomats and politicians.

So who better to offer advice to President Donald Trump on how to make the right choice to be the next US ambassador to the Vatican than Carla Powell, wife of foreign policy expert Lord (Charles) Powell, who was the confidante of British Prime Minister  - Margaret Thatcher - and one of those who instinctively understands both the role of a ambassador and how the Vatican works.

With an announcement of a new ambassador expected soon I spoke to Lady Powell from her home to see what words of wisdom she had for the president, who is expected to meet Pope Francis in May.  

Given the Vatican’s location in the heart of Rome, her remarks also include general guidance to Mr Trump on who he should appoint as his ambassador to Italy, another post he has yet to fill.  

Here are Lady Powell’s five points for the president to consider: 

1. Respect, Mr President, the history and traditions, and the political and cultural values of a country a lot older than yours.  Remember that Rome laid the foundations for much of the modern world including the US - your ambassador must think of himself or herself as someone connected to an ancient civilisation on which our own is built.  

2. Choose someone who will recognise the extraordinary skills and intellectual power of Italy's foreign policy establishment, not least its knowledge of developments in the Third World and particularly the Middle East and Africa. Remember that Italy has built global links over centuries, whether the Roman legions or Marco Polo's opening of trade routes to Cathay.

3. Avoid sending an Ambassador who is easily bewitched by charming courtiers with fictitious aristocratic titles. Choose someone who by his or her background will focus on those who represent the best of modern Italy: its engineers, its designers , its creative movers and shakers, its respected scholars . Someone who will break out of the cloying and protocol obsessed circles of Rome and embrace the real Italy.

4. Appoint someone who understands the value of using the Ambassador's dinner table for informed and sophisticated discussion under the so-called Chatham House Rule where no-one is quoted, rather than for purely social purposes . Italians  more than others conceive and express their ideas though intense and lively discussion of substantive issues . Your Ambassador should focus on the intelligentsia and those who exercise power and ignore social butterflies .

5. Make sure your Ambassador understands the global influence of the Vatican and its extraordinary network, particularly under this Pope. Even though there is a separate Embassy to the Vatican, the Church plays such a substantive role in Italy that knowing its leaders is a must for the Ambassador to the state of Italy as well.  Not for nothing do the British talk of 'Roman' Catholicism! You will find the leading figures of the Church among the wisest, most stimulating company and most informative interlocutors that your Ambassador will meet .

For many years Lady Powell has observed how the wheels of diplomacy turn and insider her villa just outside of Rome, there are photographs from some of the 20th century best known figures including Colin Powell, Tony Blair, Lady Thatcher, and Dick Cheney. 

Lady Powell also has close ties with the Vatican, helping to arrange a meeting between Lady Thatcher and Benedict XVI in 2009 while a delegation of top figures from the Holy See went to check in on her after she was rubbed at gun point at home in 2014.

Whoever becomes the new American ambassador to the Holy See will need to do some diplomatic heavy lifting given the differing global agendas of Pope Francis and President Trump. While Francis is upholding the compassionate, liberal world order Trump has struck a more nationalistic “America First” tone. Lady Powell’s advice should help the new incumbent navigate some of the diplomatic minefields.