In which direction will the most powerful military alliance in the world head over the next two years? The NATO summit in Warsaw on Friday and Saturday is supposed to show the way.
Here are the most important issues to be discussed.
Russia: The decision by Russian President Vladimir Putin to intervene in the Ukraine conflict two years ago was a shock for NATO. The alliance's eastern member states, such as Poland and the Baltic states, have felt threatened by their giant neighbour ever since. NATO has stepped up its presence in the region to reassure them, and leaders are expected in Warsaw to clear the way for more troops to be deployed. The move is expected to raise tensions with Moscow. The same goes for progress that NATO is due to mark on the creation of its missile shield in Europe, which Russia perceives as a threat. Ukrainian President Petro Poroshenko will attend the summit.
Afghanistan: A number of countries participating in NATO's training mission in Afghanistan, such as Germany and the United States, had initially planned to whittle down their presence in the country this year. But continuing Taliban violence prompted a rethink, especially after the insurgents managed to temporarily overrun the northern provincial capital of Kunduz last year. NATO leaders are expected to promise Afghanistan continued support, including financial assistance for its security forces until at least 2020.
Fight against Islamic State: The US has long been keen to incorporate NATO in its fight against the Islamic State terrorist group in Syria and Iraq, but countries such as Germany have been wary of the alliance's direct involvement. In Warsaw, the leaders are expected to take small steps, by approving the deployment of NATO surveillance planes near Syria and a return of NATO military trainers to Iraq.
Cooperation with the EU: The cooperation between NATO and EU has so far been largely limited to rhetoric because of long-standing tensions between NATO member Turkey and EU member Cyprus. But peace talks between Cyprus' Greek and Turkish communities have helped create a change. NATO has been assisting the EU with its fight against migrant smugglers in the Mediterranean Sea and is expected to offer further support to the EU's Operation Sophia off the Libyan coast. The Libyan government would, however, have to ask for the NATO assistance. The military alliance is also keen to cooperate with the EU on hybrid threats and cybersecurity.
Defence spending: NATO states have set themselves to have their yearly defence spending reach 2 per cent of gross domestic product by 2020. But many allies are stagnating at levels under 1.5 per cent. It is expected that they will face pressure in Warsaw to do more.
Cyber: NATO countries are preparing for the possibility that wars will in the future also be fought in the digital world, for instance through hacker attacks that could paralyze electrical grid or communication technology. To better prepare itself against such attacks, the alliance wants to add cyberspace as a NATO operational domain. This will allow additional resources to be made available and cyberattacks to be handled like air, sea or land attacks would be.