The Diplomat creator teases show’s future after "unnerving" season 3 cliffhanger

*Warning - contains major spoilers for all eight episodes of The Diplomat season 3*

We would never have expected anything different from The Diplomat, given how it ended its first two seasons, but the third run of the show, which is now available to stream in full on Netflix, ends with a shocking final cliffhanger setting up the already confirmed season 4.

The episode sees the Brits and Americans, still struggling to trust one another, working on what to do about a Russian sub with a powerful weapon called The Poseidon on board, which was found in British waters.

In a bid to prove their claims about the weapons, Hal and Kate concocted a new plan - the US would secretly send one of their own subs to take pictures of the weapon, which they would then show to Prime Minister Nicol Trowbridge.

However, soon after the mission was completed, Kate was told that the weapon was missing, and it didn't take her long to realise that Hal and Grace had gone behind her back and put together their own plan, to steal the weapon for the US's means.

As Kate warned that their decision could cost the UK and US their alliance, and could put the UK at risk of attack from Russia, Todd Penn, Grace's husband, also started to question Hal and Grace's relationship – do they just have a strong working partnership, or is there more going on?

With all these questions still bubbling for Kate at the end of the season, the show's creator Debora Cahn has spoken with RadioTimes.com exclusively, and broken down what the final sequence means for season 4 and for Hal and Kate's relationship.

"It continues to be the question of, ‘Do I really know this person that I've tied my life to, and do I really trust them on a fundamental level?’," she explained.

"The idea that you can still be asking yourself that question this far into a marriage, I think is really unnerving, but really true to how it goes. It doesn't get easier to maintain a long-term relationship. It takes just as much work in year 20 as it did in year one, and you've really got to wrestle with what the growth of it is."

This season of The Diplomat not only ended on a big twist but it also started with one, as Kate was passed over in favour of Hal for the role of Vice President.

It's a move that Cahn said has been the "plan for a long time", while Kate star Keri Russell said she did "relish" taking on the storyline.

The Diplomat season 3 is available to stream now on Netflix. Seasons 1-2 are also available – sign up from £5.99 a month. Netflix is also available on Sky Glass and Virgin Media Stream.

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