I know that "wage war" is an idiomatic expression that the American Heritage Dictionary defines as:

To engage in (a war or campaign, for example).

and Dictionary.com defines as:

to carry on (a battle, war, conflict, argument, etc.): to wage war against a nation.

My question is: does "wage war" mean also 'declare war" or does it refer only to the development of war operations?

3 Answers 3


The two are not synonymous.

To declare war is an announcement of hostilities, typically at the beginning, though sometimes the official declaration is made after hostilities are already in progress.

To wage war is the actual process of conducting hostile actions. It can be done with or without a formal declaration.

So, in very simple terms, declare war is what the diplomats do, and wage war is what the soldiers do.

Aside from content, declare is a point in time - you do it once, and then it is done, while wage is a period of time, an ongoing activity.


The two concepts ("declaring war" and "waging war") are distinct.

A declaration of war is a formal statement that a state of war exists. It can occur after war has started, at the beginning of a war, or before the start of hostilities.

In practice, a war can be waged without the war having been declared.

  • 4
    This is particularly important under American law, in which a formal declaration of war is rare in recent years, but "international police actions" are far more common.
    – Kevin
    Feb 15, 2016 at 23:24
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    @Kevin 's term "rare in recent years" means none since 1942. If any of the US miitary actions since then seem to you to be "wars," they were undeclared wars. Feb 15, 2016 at 23:38
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    Also, a war can, in principle, be declared without being waged. Feb 16, 2016 at 5:57
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    For example war has been declared between N. Korea and S. Korea for many decades. Yet it has not been waged for a long time.
    – Aron
    Feb 16, 2016 at 8:20
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    @Aron: Oh, a cold one's been waged. :-) And let's hope it stays cold, if it can't be ended... Feb 16, 2016 at 10:48

A nation will declare war at the outset of the conflict. After war is declared, war is waged until the conflict is over.

The declaration stage simply means that a nation has stated that it is formally at war. Once declared, war can be waged in several ways over a long period of time, including: skirmishes and battles; maneuvers and mobilization; manufacturing, supply, and logistics; training, etc.

That said, war is a complicated process with a messy history. Not all wars get formally declared. I've pretty much summarized how the two words would "normally" work in instances where war is formally declared, and then waged. In practice, this 2-step process is not always followed.

  • 1
    Many wars never had formal declarations of war. (Many wars fought by the United States were "too small" to get Congressional declarations of war.) And many other wars started years before war was officially declared. For example, the "French and Indian" war started years before the official declaration of war between Great Britain and France in the "Seven Years War".
    – Jasper
    Feb 15, 2016 at 20:25
  • @Jasper - I considered that more of a historical matter than an English one, but, at your urging, I've amended my answer to avoid any confusion.
    – J.R.
    Feb 15, 2016 at 20:30

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