The upcoming NATO summit should send a message to member states that they have the responsibility to provide the first line of defense of their own countries, the alliance’s top military officer said Thursday.

Gen. Petr Pavel, chairman of NATO’s Military Committee, said the 28-member alliance has the “strength and the determination to cope with the challenges presented by Russia,” but the first forces to respond to a crisis will always be those of the affected nation.

Members at the NATO summit July 8-9 in Warsaw will hammer out the details of the deployment of some 4,000 multinational troops in the Baltic states and in Poland in the coming months, among other measures. But those troops are not the only defense the alliance is mustering in the region, which is concerned by Russia’s actions. Some observers say the number is not very high.

Russia’s conflict with non-NATO member Ukraine has sent a chill through countries on the alliance’s eastern flank and brought more attention to military readiness.