Quite right too. Diplomacy cannot function if there can't be confidential communication between Govt and its Ambassadors for 2 key, but linked reasons.
1. Diplomats, as with other civil servants advising ministers and PMs, must be able to give an honest assessment. They must be able to speak truth to power (© Ivan Rogers).
Why is this important? Decision-makers must be able to act with as full information as possible. If diplomats are concerned with whether their advice will go down well with their political leaders, or worse, with the press and its readers, they can't provide that.
Diplomats are required to give their honest judgement - in fact they are employed specifically to do that - and confidential communications allow them to provide honest assessments. Without this, decision-makers are acting partially blind.
2. To be able to provide honest information and assessments, it is often necessary to say things privately that would either harm relations with a host country or other friend or ally if made public, or would undermine talks or negotiations with them.
This needn't be a big incident. For example, some advice to a minister about whether you think, say, France would drop its opposition to something you want, or on what it would take to get them to do that, will obviously affect the French position on that.
Of course though, it can be a big diplomatic incident, and this can have substantial effects on relationships with real-world consequences.
Whoever leaked this stuff did so maliciously and for their own ends. It could only possibly harm relations, weaken the UK's position and damage its interests.
If it was an attempt to get Kim Darroch fired (who I worked with, and who is an excellent diplomat) it is also part of a continuing attempt to undermine the impartial, apolitical civil service. As I wrote here, that's a route that goes nowhere good 9/9
Clarification in that last tweet - I didn't work with Kim, I worked (a long way) under him.
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