Image Credit: U.S. Navy (Flickr)

# Missile Defense's Real Enemy: Math

Stretching back several decades, the concept of missile defense has been hotly debated. Some well reasoned scholars argue that the United States and other countries need such defenses incase deterrence breaks down or an irrational actor gets their finger on the nuclear trigger. Others argue that missile defenses are a waste of money given that they are easily defeated, and defensive technology will always stay behind the curve — never ready for primetime.

Both sides have logical arguments. For the record, I am an advocate of missile defense — under certain conditions. With various nations all over the planet purchasing or developing ballistic and cruise weapons, defenses against such weaponry are vital — especially for the American navy in the form of Aegis missile defenses.  When it comes to missile defense in nuclear matters- I have some shall we say, complex views. For regimes such as Iran, North Korea and others when sometimes rationality is not their strongest suit — missile defense all the way. When it comes to nations with larger missile arsenals such as China or Russia, I am not sold — yet.

There is however one thing you can't argue against, simple math.

Case in point, take a look at a recent book chapter by Dr. Toshi Yoshihara in Chinese Aerospace Power (a really good book, China defense geeks I am talking to you — it's a classic — get your credit card out) from our friends over at the Chinese Maritime Studies Institute.

Dr. Yoshihara notes:

"ASBMs (anti-ship ballistic missiles) may not need to produce mission kills against the surface fleet to complicate U.S. plans. They only need to reach the fleet's defensive envelope for the Aegis to engage the incoming threats, thus forcing the defender to expend valuable ammunition that cannot be easily resupplied at sea under combat conditions. Even inaccurate ASBMs, then, could compel the Aegis to exhaust its weapons inventory, leaving it defenseless against further PLA actions. Used in conjunction with conventional ballistic missile strikes against U.S. bases and other land targets across Asia — strikes that would elicit more intercept attempts — ASBM raids could deprive the United States and its allies of their staying power in a sea fight."

Such a point raises a larger question. Will American commanders in the future face large missile forces aimed at their ships that can just simply overwhelm their defenses through sheer numbers?

Another example comes from a 2011 report from the Center for Strategic and Budgetary Analysis entitled Outside-In: Operating from Range to Defeat Iran’s Anti-Access and Area-Denial Threats (A2/AD geeks, this is truly a must read). In sketching out a scenario for a possible Iranian A2/AD campaign between 2020-2025, the authors explain:

"Iran could deploy its land-based ASCMs (anti-ship cruise missiles) from camouflaged and hardened sites to firing positions along its coastline and on Iranian-occupied islands in the Strait of Hormuz while placing decoys at false firing positions to complicate U.S. counterstrikes. Hundreds of ASCMs may cover the Strait, awaiting target cueing data from coastal radars, UAVs, surface vessels, and submarines. Salvo and multiple axis attacks could enable these ASCMs to saturate U.S. defenses…salvos of less capable ASCMs might be used to exhaust U.S. defenses, paving the way for attacks by more advanced missiles."

Think about it — could we someday see a scenario where American forces at sea with a fixed amount of defensive countermeasures facing an enemy with large numbers of cruise and ballistic weapons that have the potential to simply overwhelm them? Could a potential adversary fire off older weapons that are not as accurate, causing a defensive response that exhausts all available missile interceptors so more advanced weapons with better accuracy can deliver the crushing blow?

Simply put: does math win?

Truth be told, this is a very simplistic way of looking at the classic missile vs. missile-interceptor game. Many complex scenarios could be easily envisioned. Sea-based forces on the defensive would likely employ multiple methods to secure themselves. Jamming of missile and land-based guidance systems, counterstrikes on enemy missile launchers and attacks on enemy command and control would all likely be employed on some level once offensive missiles are launched. Preemptive strikes could also be employed if a credible threat of a launch was presumed. Not to mention possible available land-based interceptors could be in the mix depending on the area of hostilities as well as cyber and UAV strikes. And this says nothing about nuclear weapons…

Yet, you have to wonder, math does have a powerful say in such a scenario. And considering the cost of missile defenses vs. offensive missiles, "math" seems to have some valid arguments.

What do you think?