By Andrew Hammond, The Centre for International Affairs, Diplomacy and Strategy–

On Friday, British Prime Minister Theresa May will become the first world leader to meet with Donald Trump since he was sworn in as U.S. President. The meeting breathes new life into the long-standing “special relationship” between the United States and Britain, with Mr. Trump already calling her “his Maggie,” drawing comparisons to the political bond forged between Ronald Reagan and Margaret Thatcher in the 1980s.

Despite the many political differences between Ms. May and Mr. Trump – at first glance significantly larger than those between Mr. Reagan and Ms. Thatcher – both leaders would welcome a constructive partnership that builds on the traditional ties between the two countries, ties founded on demographics, religion, culture, law, politics and economics. For Ms. May, the rekindling of this special relationship, in a post-Brexit context, would potentially add some credence to her aspirations for a new “global Britain,” while Mr. Trump’s as-yet untested credentials as a leader on the world stage would be burnished.

At the heart of Friday’s discussions will be to set the early groundwork for a potential trade deal in the coming years. This would be a boon for Mr. Trump, given that he is being largely portrayed as a protectionist President, especially after his abrogation on Monday of U.S. participation in the Trans-Pacific Partnership. At the same time, if Ms. May could secure a U.S. trade deal, it would represent a significant win in her battle to show that Britain can, post-Brexit, secure new deals with key partners outside the European Union.

There are key trade areas ripe for agreement, including lowering or eliminating tariffs on goods. Potential icebergs lie on the horizon, however, not least Mr. Trump’s commitment to “America First” and the fact that any deal could not be finalized – under the terms of Britain’s membership in the EU – until after the country leaves the supranational body.

One area of potential disagreement is the prospect of harmonizing financial regulations between the two countries, given the international dominance of Wall Street and the City of London. Another key agenda item will be security and defence, particularly with respect to the close partnership between the two countries in areas such as intelligence and special forces. There will be obvious agreement over the need to continue the counterterrorism battle against the Islamic State, but tensions could surface on NATO, and Russia in particular. Mr. Trump has repeatedly called NATO “obsolete” and engaged in open political courtship with President Vladimir Putin. Ms. May, however, is a strong defender of NATO and confirmed earlier this month that Britain would, under its Article 5 responsibilities, come to the aid of any Eastern European countries attacked by Moscow.

Ms. May will be keen to find out Mr. Trump’s real bottom lines on these issues and, in the words of Ms. Thatcher, seek to “stiffen his spine” against what she perceives as the real and present Russian threat. Mr. Trump appears to believe Russia is not a serious danger to the United States and that there is scope for rapprochement, hinting this month he could drop economic sanctions if Russia “is helpful.”

Lack of clarity on U.S. policy toward NATO is one driver spurring EU countries to move toward reversing a decade of defence-spending cuts, totalling around 10 per cent in real terms. Moreover, a new European Defence Action Plan was discussed at last month’s EU summit that, subject to any final agreement, will see greater continental military co-operation.

Given the uncertainties ahead in the Trump presidency, Ms. May likely will try to play the role of a trusted, albeit candid, friend in a bid to make the relationship work as smoothly as possible. This should provide some protections for bilateral relations in what could be a rocky few years internationally, even if strong personal chemistry fails to take root between the two leaders.

However, while this may be a sensible strategy, at least initially, it is not without risk, given Mr. Trump’s erratic nature and polarized standing in U.S. and international opinion. While seeking the potential upside in the new relationship, including the possibility of a trade deal, Ms. May would be wise not to overestimate Britain’s ability to shape U.S. power or be blind to the fact that Mr. Trump’s “America First” outlook may – ultimately – care little for British interests.