Final answer:
A country that pursues foreign policy objectives alone, without the collaboration of others, is acting unilaterally. This is in contrast to approaches like liberal internationalism or selective engagement, which involve varying degrees of global participation and cooperation.
Step-by-step explanation:
If a country acts alone in pursuing its foreign policy objectives without consulting or cooperating with other countries, then it is said to be acting in a unilateral manner. This approach contrasts with liberal internationalism, which involves proactive engagement and cooperation in a community of nations. Conversely, neo-isolationism represents a policy of distancing, notably from international organizations, while selective engagement indicates maintaining a strong military presence and remaining actively involved on the global stage. The concept of the North Atlantic Treaty Organization (NATO) underscores the importance of collective defense agreements, while protectionism refers to policies that shield a country's domestic industries from foreign competition.