The prime minister's announcement about the merger between the Foreign Office and the Department for International Development came in two parts.
The opening statement to MPs, the bit that had been written and overseen by officials, had a clear argument.
It was all about joining up policy, ending false distinctions between diplomacy and development, creating one department that can mobilise all Britain's assets overseas.
But once Boris Johnson was facing hostile questions from sceptical MPs, his tone changed and his more instinctive arguments came to the fore.
For too long, he said, Britain's aid budget had been seen as a cashpoint in the sky, detached from British diplomatic and commercial priorities.
Voters will want to see that the government is spending aid efficiently.
This is an opportunity, he said, for the UK to get more value from the huge investments that it makes in overseas spending.
This is the tension that lies at the heart of this policy change. How much is it about making British foreign policy more effective and more coherent? And how much is it about satisfying those Tories who believe much foreign aid is wasteful and should be bent more to the will of British interests?
For Mr Johnson, this is business that is long overdue.
As foreign secretary, he looked avariciously at DFID's £15bn aid budget. He saw how it was DFID officials who had the power in many embassies around the world. And he learned of the tensions between two departments that at times had different priorities.
As prime minister, he came to see the diffuse nature of UK foreign policy, dispersed between the FCO, DFID, the National Security Council and Downing Street, not to mention the departments for trade and business. So bringing this all together made sense to him.
And he knew it would be controversial, although he might not have imagined that no fewer than three former prime ministers would weigh in against him, including one from his own party.
International charities have long feared this merger might happen. They believe it may mean the UK's commitment to using its powerful aid budget to reduce poverty will be watered down.
And the prime minister made this clear in the Commons. Yes, reducing poverty will, he said, remain central to the mission of this new Foreign, Commonwealth and Development Office.
But he also suggested less money would go to Zambia or Tanzania, and more would go to Ukraine and the Western Balkans where there are vital European security interests.
Yes, he said, the UK will remain committed to the target of spending 0.7% of its income on overseas development assistance. But his officials also made clear that the current integrated review of UK foreign policy will look again at redefining what actually counts as aid.
To some Conservatives, the aid sector is too protective of its sacred cows, too unwilling to think differently about aid, even to accept that sometimes the UK national interest and reducing poverty can be the same thing.
But to the pessimists, they fear the UK will now start spending more aid on curbing immigration, improving security and boosting British trade interests.
The tricky question is the timing. Labour accused Mr Johnson of playing politics, of making the announcement today to distract from his health and economic crises.
Government officials insist the PM just wanted to get the new department up and running this autumn so that it is well placed to handle the UK's presidency of the G7 and COP26 summit on climate change next year.
But in the midst of a global pandemic, which Mr Johnson admits is forcing change in the way the UK does its foreign policy, some will wonder if this is the right time for Whitehall officials to start moving the chairs and changing the nameplates.
The former British ambassador to Cairo and one time foreign policy adviser to David Cameron, John Casson, said the hope is that the merger will blend the best of the FCO's political agility with the best of DFID's delivery skills. His fear is that the new department may comprise the worst FCO short termism with DFID's bureaucratic caution.
Nonetheless, Boris Johnson has made his choice.
He has decided how he wants to retool his government to deliver its global Britain foreign policy.
The only problem is he is still working out what that policy should be. That 'integrated review' of the UK's entire overseas strategy is not due to report until the autumn.
It will not be the first time that a cart has been driven before a horse along the streets of Whitehall.