In Stephen Walt's essay "Alliances: Balancing and Bandwagoning," he presents a framework for understanding international relations not unlike the relationships found in game theory. The nature of an alliance depends on a state's response when facing an imminent, proximate threat. It can either choose to balance, that is, to form an alliance with a nearly equal or weaker state to curb the influence of a more powerful state, or if it is a weak state itself, with no other allies available, it can choose to bandwagon, that is to align itself with the threatening state.
But the innate power of a foreign state is not the sole influence on an alliance choice; aggregate power, geographic proximity, offensive power, and the aggression level of its intentions must also taken into consideration by threatened states.
Although it might seem natural for a powerful state to choose a bandwagoning strategy when seeking to subordinate numerous client states, the implicit aggressiveness this involves is inherently volatile and potentially destabilizing. This is why, in most scenarios, balancing is most often preferred by statesmen, regardless of the power of their state; no one can be completely sure of what another will do.
In peacetime and the early stages of war, states are more likely to choose to balance, to combine their forces, to defeat their greatest threat, but they will bandwagon with the winning powers once victory seems certain. However, the choice of balancing remains the most common in international relations due to its stabilizing influence.