I am certain that many Britons are as appalled as I am about the horrific scenes coming out of Syria.
The use of chemical weapons is barbaric. It is a crime against humanity and it is a clear violation of international law.
The Liberal Democrats are an internationalist, outward-looking party - and part of that is being willing to play our part in upholding international law.
In the next few days, it is possible the Government will ask MPs to decide on potential military action in Syria. This is not a decision we will ever make lightly.
As Leader, I want to be clear with you how I and our group in Parliament will make such a decision.
Firstly, in advance of any debate or vote, the Government should share with Parliament what evidence it has of the Syrian Government’s involvement, and that of their Russian backers, in last weekend’s attack.
Secondly, the Government must present the objectives of any proposed action to Parliament. Any proposed action should be targeted at reducing the capacity of the Syrian regime to repeat these attacks.
Thirdly, any response should be on a multilateral basis. A unilateral response by any country, outside of a wider strategy, without the support of their allies is not the way forward.
And of course, there MUST be a full and frank debate and vote in the House of Commons ahead of any military action.
We will judge any military action the Government proposes against these tests.
This is not a decision we will make lightly, or without the fullest consideration of the evidence.