by Christopher Black, New Eastern Outlook:

The United States of America is at war with Russia. There is not much point in using terms such as “proxy war” to describe the situation. If a belligerent in a war is acting as a proxy for another power and that power is not engaged directly in the war, the term can be useful. But when the power, for which the “proxy” engages in the war, is directly involved in the war itself, then it is a co-belligerent, a party to the war directly, not simply by proxy.

The issue is whether each state is pursuing its own interests and has its own independent means of doing so, or whether the interests and forces of the allied powers are subordinate to the interests and forces of a leader.  In such a case, the enemy being attacked can regard all its opponents as a single entity.