The force will have remote projection capabilities:

Most dramatically, the NATO heads of government could announce creation of a multi-national rapid deployment force of about 21,000 troops that would allow NATO to operate quickly and effectively against new enemies far from Europe, the area NATO was formed to protect against the Soviet Union 53 years ago. NATO members may also announce commitments to acquire new aircraft and equipment that would make this an effective force and allow it to deploy on a week's notice.

This can be interpreted as a way that the Europeans can signal a willingness to stay allied with the US.