Imagine aid spending as an archery target.  At its centre is emergency relief, the core function of aid: relief for people who are victims of flood, famine, earthquake or war.  For example, those rendered homeless by tsunamis in Asia or war in Syria.

The next ring out is basic provision that is not necessarily emergency relief: clean water, say, or sanitation.

Further out still is immunising children against preventable diseases: Rotaviruses or Hepatitis B or polio or  – not itself basic provision, but still close to the target’s centre.

Then comes schools and hospitals.  Eventually, one reaches national-building: securing property, and economic help.  And then climate change adaptation and mitigation.

Our members’ panel survey of five years ago, the last time we looked at the subject in depth, found exactly what one would expect to find.

Being sensible people, the Conservative members we surveyed showed decreasing support for aid as it left the core of emergency relief and travelled to the outer rings of nation-building.

Essentially, they were all for aid that clearly makes an immediate difference, but were unconvinced that cash for securing property rights, for example, either provided taxpayer value for money or should be an aid objective at all.

The percentages may well have changed in five years.  But it is very unlikely that the basic shape of the panel’s view has altered much.

Which suggests that the Government’s absorption of the Department of International Development into the Foreign Office is a mistake.

For the essence of Boris Johnson’s statement today was not that the 0.7 per cent aid spending target is to be taken out of law – a move that we would welcome, because its putting into law was virtue signalling, no more, no less.

Nor was it that the target will be dropped altogether – about which we would be indifferent, if only because there is no magic in yoking one’s aid spending to a fraction of one per cent (or of any per cent).

Rather, the Prime Minister’s intent was to signal that overseas aid is become an instrument of foreign policy: exactly what our panel, when it mulled taxpayers’ money for democracy-building or property rights, was sceptical about.

He told the Commons that foreign policy and international development are basically “one and the same endeavour”.  But this is the logic that Tory members rejected, and one of his own examples helps to show why.

Johnson referred to assistance given to six Balkan countries to counter “Russian meddling” – nations, incidentally, that are waiting to enter the EU’s revolving door in the wake of the UK exiting from it.

Two years ago, Theresa May joined EU leaders in promising regional security cooperation to help tackle common corruption, organised crime, the trafficking of people, drugs and firearms, and terrorism plus violent extremism.

All well and good – but the move was nothing much to do with aid, if the guiding impulse behind the latter is, as it must necessarily be, humanitarian feeling rather than the national interest.

The Prime Minister complained that too many cooks spoil the aid broth, and that it makes sense to bring aid spending within a single department.  But he gave no reason why it should be the Foreign Office rather than DfiD.

Admittedly, some former DfiD Ministers complain that the department’s ethos is focused excessively on its client base and insufficiently on the taxpayer.

But the more one probes the evidence, the more one comes to see that much of the most egregious mis-spending is associated with other departments: BEIS with India and the Foreign Office with China.

One assessment found that only five per cent of the £765 million then spent by former and 16 per cent of the £1 billion then spent by the Foreign Office went to the countries that needed it most.

Frankly, Johnson’s statement was as clear as mud when it came to what the continuing 0.7 per cent of GDP will actually be spent on, and what the costs of shuffling the Whitehall deckchairs will be.

Furthermore, the change creates a brand new cart to put before the horse – that’s to say, the awaited defence and security review, which is likely to see traditional defence interests squaring off against enthusiasts for cyber.

The wider significance of the proposal is that it appears to reflect the thinking of John Bew, the Prime Minister’s foreign affairs adviser, who is contributing to the review.

Bew is the author of a fine biography of Clement Attlee, one of the architects of the UK’s post-war policy, and is essentially a pro-intervention “muscular liberal”.

Since Britain can’t and shouldn’t withdraw from such international institutions as the WTO, NATO, the G7 and the Council of Europe, his presence is a plus, in the round: a necessary check on any drift to isolationism.

And although we disagree with this particular merger, it can’t be said that it comes as a surprise.  It was clearly presaged by the post-election merger of Foreign Office and DfiD Ministers.

Supporters of the move would point out, not unfairly, that it shows the Government isn’t marooned – rendered inert by the pressures of dealing with the Coronavirus.  Johnson has made a decision and is taking action.

Tom Tugendhat wrote recently on this site that bringing together aid, foreign policy and trade “would help to cut the strings that see Beijing’s loans deliver UN votes or silence over abuses”.  The point is worth mulling.

We expect that the proposed change polls well.  It is part of the transition from the age of the Cameroon modernisers to the era of Dominic Cummings, with its hard-nosed sense of what plays in Red Wall Country.

None the less, remember what caused DfID to be brought into being in the first place.

The Pergau Dam deal during the mid-1990s sought to combine aid, arms sales and building a dam of dubious value in Malaysia.  The consequent court case discredited the then Foreign Office-led model of providing aid.  We are unconvinced that it is necessary to reinvent this particular wheel.