The world was shocked by the downing of flight MH17 over Ukraine with the loss of all 298 people on board. The subsequent failure to allow the victims to be identified and returned to their families for burial has compounded the distress.
The disaster was particularly poignant for me, as I knew one of those who was killed: the World Health Organisation's media officer, Glenn Thomas. Glenn worked with a number of MPs who focus on the prevention of global disease, in my case through the All Party Parliamentary Group on Global TB, and the news of his loss came as a great shock.
Glenn, along with many others on that plane, was on his way to the world AIDS conference in Melbourne. As I said in the Commons on Monday, the values epitomised by that conference, and the World Health Organisation’s work in general, of internationalism and human rights, stand in stark contrast to the disregard for human life shown by Russia's aggression.
The international community has been slow to respond to President Putin's territorial ambitions. Russia has annexed Crimea, invaded Georgia and bullied its neighbours, yet our collective reaction has been dangerously weak. I believe that the House of Commons’ failure to endorse military action in Syria last summer - unpopular though that cause was - in response to the use of chemical weapons was particularly damaging.
Although Russia was expelled from the G8, it retains its permanent seat on the UN Security Council with the power to veto concerted international action in the world’s most difficult areas.
It is right that further sanctions are being imposed, but they do not go far enough. Germany relies on Russian energy supplies, while France has large arms contracts outstanding. Self-interest is preventing Europe from taking the action that is required.
One constituent suggested to me this week that we should commit troops to the Ukraine. That would be a step too far, but we are in danger of descending into another Cold War, and of failing to demonstrate the resolve needed to check Russia's ambitions.
Hand-wringing is not enough. History warns us that we need to show strength and unity in the face of an aggressor, or pay the price with more lives lost.