British Prime Minister Theresa May will tomorrow become the first world leader to meet with Donald Trump since he was sworn in as US president last week. The meeting breathes new life into the long-standing 'special relationship', with Mr Trump already calling her "his Maggie", drawing comparisons with the political bond that was forged between Ronald Reagan and Margaret Thatcher in the 1980s.
Despite the many political differences between Mrs May and Mr Trump, on the face of it significantly larger than those between Mr Reagan and Mrs Thatcher, both leaders would welcome a constructive partnership which builds on the traditional ties between the two nations.
For Mrs 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 tomorrow's discussions will be setting the early ground work for a potential US-UK trade deal in coming years. This would be a boon for Mr Trump given that he is being criticised, in many quarters as having the hallmarks of an anti-globalisation, protectionist president, especially after his abrogation on Monday of US participation in the massive, proposed Trans-Pacific Partnership trade and investment deal. At the same time, if Mrs May could secure a US trade deal it would represent a significant win in her battle to show the UK can, post-Brexit, swiftly secure new trade deals with key economic partners outside the EU.
There are key areas ripe for agreement, including lowering or eliminating tariffs on goods. Equally, however, potential icebergs lie on the horizon, not least given the president's commitment to 'America First', and the fact any deal could not be finalised - under the terms of the UK's membership of the EU - until after the nation leaves the supranational body.
Areas of potential disagreement on trade include the prospect that harmonising financial regulations between the two countries, with the international dominance of Wall Street and the City of London, will not be straightforward. Meanwhile, securing agreement in other sectors, including agriculture, where there is also divergence of views and strong interest groups, will not be easy either.
Another key agenda item will be security and defence, which has long been at the core of the special relationship given the very close partnership between the two nations in the post-war era.
So while this is a terrain in which there will be much agreement, including over the need to continue the counter-terrorism battle against Isil, tensions could surface on Nato and Russia, in particular.
Mr Trump has repeatedly called Nato "obsolete" and asserted the need for greater burden sharing of alliance costs between the US and Europe. Plus, he engaged in open political courtship of Russian President Vladimir Putin. However, Mrs May is a strong defender of Nato and confirmed earlier this month the UK would, under its Article 5 responsibilities, come to the aid of any eastern European countries attacked by Moscow.
Mrs May will be keen to find out Mr Trump's real bottom lines on these issues and, in the words of Mrs Thatcher, seek to "stiffen his spine" against what she perceives as the real and present Russian security threat.
Mr Trump appears to believe Russia is not a serious threat to the United States, and that there is scope for rapprochement, hinting this month that he could drop economic sanctions if the country is "helpful". Specifically, he perceives there are common interests over issues such as preventing Iran securing nuclear weapons, combating terrorism, and potentially even helping contain a rising China in a new global balance of power.
Yet, US Defence Secretary James Mattis said this month that "Russia is raising grave concerns on several fronts", including trying to "break the Northern Atlantic alliance (Nato)...which needs integrated steps - diplomatic, economic, military and the alliance steps...to defend ourselves where we must".
Already, lack of clarity over US policy toward Nato is one driver spurring EU countries to move toward reversing around a decade of defence spending cuts, totalling around 10pc in real terms, which will be welcomed by Mr Trump. 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 multiple uncertainties ahead in the Trump presidency, Mrs May is likely to seek to play the role tomorrow of a trusted, albeit candid, friend in a bid to get close to the president to try 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 of international relations to come, 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, especially given Mr Trump's erratic nature and polarised standing in US and international opinion. While seeking the potential upside in the new relationship, including the possibility of a trade deal, Mrs May would be wise not to overestimate the UK's ability to shape US power, and be blind to the fact that Mr Trump's 'America First' outlook may - ultimately - care little for UK interests.
Andrew Hammond is an Associate at LSE IDEAS (the Centre for International Affairs, Diplomacy and Strategy) at the London School of Economics