Every so often I see it asserted that the deployment of a certain kind of military force or system into a specific area would not be provocative to a potential adversary because would be ‘readily recognizable as a purely defensive capability,’ e.g. something that could not be used for offensive purposes and therefore the opponent ‘will tolerate.’
For
example, a country defending a land border might opt to deploy light ground
forces armed with short-range anti-armor/personnel weapons in frontal areas
during peacetime to increase the likelihood of bogging down any potential
ground offensives by an opponent. In contrast, this defender might garrison its
heavier armored and artillery forces far enough in the rear so that it would be
virtually impossible to rapidly and covertly sortie them for offensive
operations against the opponent’s own territory.
Another
example might be placing anti-air systems in locations where they could only be
used to defend one’s own (or an ally’s) territory; e.g. they would lack the
reach for any other purpose. The same would be even more true for ballistic
missile defense systems.
These
kinds of deployments would be “purely defensive” by any reasonable standard.
And yet they could still be highly provocative. How is this possible?
Even purely defensive assets are
often interpreted by one side as means by which the other seeks to reduce its
vulnerability to deterrence. An opponent may also be provoked if it perceives
it is less able to successfully threaten or employ military force for grand
strategic compellence due to the defender’s improved denial or punishment
capabilities. Inadequate geographic buffering between the two sides further
reduces any “margin for error.”[i] It is simply
impossible for deterrence to avoid arousing some degree of fear or resentment
in a potential adversary.
By
this logic, a potential adversary whose peacetime foreign policy rests on the
ability to militarily menace the defender would be provoked by the loss of
coercive clout. Or the opponent might interpret the “pure defense” to be a shield
that reduces the defender’s vulnerability to retaliation if the defender was to
use other forces to attack the opponent first. The opponent might not pursue
war over these kinds of defensive deployments, but it would likely take actions
using some or all of its tools of national power to offset the defender’s moves
or ‘punish’ the defender for its ‘audacity.’ In the military sphere, the
opponent might double down on fielding offensive capabilities and capacity. The
opponent might even seek to provoke a crisis with the aim of manipulating the
defender into limited concessions.
None
of this means the defender should not field the forces it deems necessary to
defend itself or its allies from attack. Far from it! My point is that a
belligerent potential adversary is going to be provoked to some degree no
matter what defensive moves the defender takes. Yes, defensive force
deployments that increase crisis instability ought to be avoided. Under some
situations, a force deployment might not be worth the provocations it would
likely elicit. All the same, the defender has the inherent right to protect his
sovereign territory and his allies’ sovereign territories.
There’s
an added wrinkle, though, in that it will rarely be possible to field a true
“pure defense.” Strategic and operational defense often requires some tactical
offense. For instance, a potential adversary might imply he’d use his own
territory as a sanctuary for bombarding the defender’s forces or territory, or for
pressuring the defender’s sovereign air and waterspace (as well as the
international approaches to both). The defender would be justifiably motivated
to deploy tactically offensive systems into positions and postures from which
they could quickly (but not necessarily immediately) threaten either the
aggressor’s offensive systems or countervailing targets.
Likewise,
many systems are inherently usable for both defensive and offensive purposes.
For example, a country might declare that anti-air and anti-ship missile
batteries placed in coastal areas are intended solely for territorial defense,
but the reality is that their reach might pressure an opponent’s ability to
move sea and air forces (or commerce) through the covered areas. That kind of
effect might or might not be deliberate; the other side will be provoked either
way.
The
approaches the defender uses to place tactically offensive capabilities in the
field can be calibrated. Not all of these kinds of forces need be placed far
forward at high readiness postures; those with particularly high campaign-value should be held in rearward areas during peacetime or a crisis in order to
reduce their vulnerability to an opponent’s preemptive strikes. Reciprocal
confidence-building measure regimes can also help reduce the risk of provoking
an opponent’s fears. But it takes both sides’ goodwill and commitment to peace
for a regime like that to function. In the absence of such cooperation, a
well-meaning defender will have to accept that the measures he deems essential to ensuring defensive effectiveness will be provocative to his opponent. The costs and risks of a given defensive move under consideration will have to be weighed against the costs and risks of not making that move. There’s never a free lunch for a defender, and pretending
otherwise is misguided.
The views expressed herein are solely those of the author
and are presented in his personal capacity. They do not reflect the official
positions of Systems Planning and Analysis, and to the author’s knowledge do
not reflect the policies or positions of the U.S. Department of Defense, any
U.S. armed service, or any other U.S. Government agency.
[i] Janice
Gross Stein. “Deterrence and Reassurance,” in Behavior, Society, and Nuclear War, vol.
2, eds.
Philip E. Tetlock et al. (New York: Oxford University Press, 1991), 17. It is not clear such a thing as a
geographical barrier even exists in the age of long-range aerospace strike.