I think it is a very important step in the right direction that the Afghans have taken over responsibility for the security in their own country, and NATO being able to end its combat presence in Afghanistan.

Turkey's a valued ally, important ally for NATO, not the least because of its strategic geographic location, bordering Syria and Iraq and close to Russia and the Black Sea.

Reconquer the streets, the markets - the public spaces, with the same message of opposition: We are devastated, but we will not give up. With torches and roses, we deliver this message to the world: We do not let fear break us. And we do not let the fear of fear silence us.

As long as NATO changes when the world is changing, we will be very important for the security of all our allies, including the United States.

What NATO troops are doing in Afghanistan is to train, assist and advise Afghans, but they are actually doing the fighting. They are actually taking the responsibility for the security in their own country. And that is a great achievement, compared to what we saw just a few years ago, when NATO troops had to conduct the combat operations fighting the Taliban.

After many, many years of decline in defense spending across Europe and Canada, in 2016, we saw the first significant increase. We still have a long way to go, but at least European allies have kind of started move in the right direction.

We are living in a world in which developments are harder to predict and one that has become more uncertain. In such a world, you must be prepared for the unpredictable. Nobody predicted the fall of the Berlin Wall or the Arab Spring.