Idealists say aggression is fundamentally unacceptable. Realists say Russia is so strong that resistance is futile and acceptance is the only answer. Well, I say we are strong enough to defend our ideals, and fighting back is the most realistic choice. Here's why. 👇🧵1/16

Russia is attacking Ukraine not because of a threat, a diplomatic dispute or a broken promise. Russia is attacking solely because, in the Kremlin's view, Ukraine is weaker and therefore attackable. In other words, the attacks would stop if Ukraine was stronger. 2/16

We have gone back to the times of geopolitical power competition. International law and the UN Charter are being ignored and overridden by force. We must therefore increase our own strength to reverse this trend. 3/16

If Russia senses that our support is failing to alter battlefield dynamics (if we don’t send enough or if we set irrational limits on use) then we invite continuation. But if Russians see that our support will never stop, and might increase – their calculations will change. 4/16

And this goes way beyond Ukraine. If our deterrence of Russia is credible, it can change the calculations of other would-be aggressors. In this way we strengthen the rule of law, the UN charter and the other basic principles that make the world a safer place. 5/16

The Western objective has to be maintaining a favourable power balance. The most rational way to do this is to maintain a constant or increasing weapon supply that would in the short to medium term put Ukraine in a stronger position on the battlefield. 6/16

At the same time, we must offer Ukraine collective security guarantees that would be credible enough to keep the power balance in Ukraine's favour in the medium to long term. 7/16

I have said many times that without a clear Ukrainian victory there is absolute certainty that Russia will attack again. All previous attacks were initiated on false pretences, so similar excuses will be found in future if Russia ever feels able to restart hostilities. 8/16

As long as there is a credible risk of a renewed Russian attack, large-scale rebuilding will be very difficult. The many billions of dollars needed will have to be covered by private bank loans and private insurance guarantees, and that requires predictable stability. 9/16

Stability would not only attract investment back into Ukraine, but also provide the conditions necessary for refugees to have the confidence to return and rebuild. 10/16

A stable political environment is also a fundamental requirement for effective EU integration. Case studies of other countries that joined the EU long before joining NATO are not applicable to Ukraine, because Ukraine is still in immediate danger. 11/16

Some are considering security guarantees tailored towards Ukraine on the South Korea / Japan model. But for that to be credible, we will have to involve the US and other major NATO allies anyway, probably also stationing some sort of contingent in Ukraine permanently. 12/16

For Ukraine, Article 5 could be much quicker and more practical than a specially written agreement. Ukraine is close and already using NATO equipment to great effect, so it would actually be simpler to bring them into NATO than to create something from scratch in parallel. 13/16

And let us not forget – Ukraine has the largest and best battle-hardened army in Europe. They face the enemy NATO was founded to face. If we want to be well prepared to face Russia in the future I would much rather be in an Alliance with Ukraine than without. 14/16

To sum it up. If we want Ukraine, Europe and the transatlantic area to be secure from an evermore aggressive Russia we have to accept Ukraine into NATO, build up our defences, and thereby bring back respect for the UN Charter and international law. 15/16

NATO was made to secure peace in Europe through collective defence against Moscow. I am saying NATO should do more of what NATO was made to do. 16/16🧵