Even superpowers suffer local military defeats. On March 8, 1965, 3,500 US marines landed at a beach near the Danang airbase in Vietnam. On December 25, 1979, the Soviet 40th army crossed the border into Afghanistan. Less than a decade later, the last US and Soviet combat troops pulled out of Vietnam and Afghanistan, having suffered 58,000 and 15,000 combat deaths, respectively. The Sicilian expedition, launched by Athens in 415 BC, ended with the total defeat of its deployed naval and land forces. Arguably none of these defeats was strategic in nature. The defeat on the battlefield was not decisive in determining the outcome of the broader systemic conflict underway. Undoubtedly, the war in Afghanistan (1979- 89) represented a tangible drain on Soviet resources and the US involvement in Vietnam (1955-75 or 1965-73) weakened the US economy. But neither military conflict decided the outcome of the Cold War. Similarly, Athens’ military defeat in Sicily (415-413 BC) did not prevent it from continuing the Peloponnesian War (431-404 BC) for almost a decade.
Why did the superpowers of their day launch – in retrospect, disastrous – peripheral military campaigns? First of all, it is worth noting that all three powers had intervened abroad before, and relatively successfully so. The USSR intervention in Hungary and Czechoslovakia, the US intervention in Korea and the Athens’ brutal suppression of the revolt in Melos, for instance, were all successful in defending the status quo. Due to “imperial policing”, Hungary and Czechoslovakia remained in the Soviet sphere of influence and South Korea remained in the US sphere of influence and in fact became a US forward operating base at the end of the war. Athens prevented defections and strengthened alliance cohesion, while admittedly transforming itself from a primus inter pares into a hegemonic, quasi-imperial power within the Delian League.
All three interventions were underpinned by a defensible strategic rationale. Whether in fact decision-makers explicitly referred to this rationale is for historians and detailed historical research to answer. At the strategic level, Afghanistan was hard fought over during much of the 19th century. Seen as the gateway to India (the jewel of the British Empire), it was located at the fault line between the British and Russian spheres of influence. While it is far from certain that Russia had any designs on India, Britain wasn’t so sure and fought three wars in Afghanistan in less than a century, largely to pre-empt Russia from establishing a foothold there and as part of what Kipling called the “great game”, the Anglo-Russian antagonism in Central Asia. If Afghanistan was the gateway to India, so it was a gateway to the Soviet Union. The Soviet decision to invade Afghanistan was primarily motivated by worries that it might drift closer to the United States (NYT, January 29, 2019). Vietnam was historically less coveted, but the US position in Asia seemed to call for a robust defence in order to prevent other states in South-East Asia from realigning themselves with China or Russia (domino theory). Athens pursued what to modern eyes looks like “indirect approach”. The decision to invade Sicily was meant to strike Sparta in its rear and interdict food exports from Sicily to the Peloponnesian League. In this sense, Athens’s intervention was offensive, compared to the more defence-motivated actions taken by the USSR and the US.
Vietnam, Afghanistan and Sicily are often regarded as military disasters and strategic setbacks. While all three interventions proved military failures or, in the case of Athens, outright disasters, it is less obvious that they should be considered strategic defeats. The United States lost militarily and it failed to achieve its immediate political objective, that is, prevent South Vietnam from being wrested from the US sphere of influence. However, the strategic rationale for the Vietnam intervention had been to prevent South-East Asia from turning “communist” and re-aligning itself with the USSR or China. The other (major) dominoes did not fall. Similarly, the USSR suffered defeat on the battlefield, but it prevented Afghanistan from realigning itself with the United States. Only Athens failed to achieve its strategic objective, for it suffered total defeat and it failed in its strategic objective to weaken the Peloponnesian League by knocking Sicily out of the geopolitical picture. Of the three, only Athens can be said to have failed to achieve its original strategic objectives, even though all three suffered military defeats.
This leaves unaddressed the question whether the (undoubtedly higher than anticipated) loss of life, treasure and reputation was worth it in light of the underlying rationale. Athens did fight on for another decade. But the Sicilian disaster had not only imposed heavy material losses, but it had also weakened its international prestige. The wars in Afghanistan and Vietnam sapped Soviet and US economic, financial and material power as well as morale and, arguably, their international reputation. While the military defeats were not strategic in nature, the interventions were costly, even if they did not weaken the three powers irretrievably. The USSR did collapse and the Afghan was not helpful in this respect, but it probably was not the main cause. Ultimately, of course, any assessment of whether the strategic rationale for intervention and whether the price paid in the end was commensurate with the objective depends on one’s counterfactuals, that is, what would have happened absent military intervention. Difficult to say, even in retrospect. The point is that the interventions should not be written off as strategic defeats (only because they ended military defeat) or as unaffordable adventures.
Any evaluation of the decisions to intervene is highly dependent on the assumed the risk-reward trade-off. Surely, none of the three anticipated military defeat when deciding to intervene. All of three of them suffered defeats. Any military venture and especially overseas interventions are inherently risky. The latter give local and global adversaries an opportunity to tie down the intervening power and make intervention costly and ultimately unsuccessful (Coll 2005). Foreign interventions often involve substantial logistical challenges that limit battlefield effectiveness. Setbacks may quickly affect morale given the relatively greater difficulty to justify the loss of life and treasure in overseas “adventures”. Foreign policy decisions, including decisions to intervene in far-flung places or the “near abroad” are necessarily made on the basis of incomplete information and epistemic uncertainty. They face additional challenges due to unintended consequences and, most crucially, the challenge of anticipating the strategic behaviour of actual or potential adversaries. Such risk-reward calculations necessarily involve subjective judgments and probabilistic calculations. In the case of Sicily, Afghanistan and Vietnam, historians will need to sort out what the biggest miscalculations were with respect to misjudging the probability of military defeat.
While perhaps not hyper-consequential, non-material losses may have been more problematic than the direct material losses and financial costs incurred by the failed interventions. In case a major power suffers a limited military defeat, allies may start to have second thoughts about its ability and willingness to maintain its alliance commitments and adversaries may spot an opportunity to exploit a tactical setback strategically by ramping up the pressure. The locally defeated hegemon may be less willing to shoulder costs and it may be (slightly) more resource constrained. This may alter the way both allies and adversaries perceive it and its ability and willingness to engage in future conflict. Non-strategic defeats often affect the attitudes of allies and adversaries alike. In Greece, for instance, the defeat in Sicily encouraged Athens’ enemies in Persia to move more forcefully against Athens and fostered rebellion in the Aegean. Similarly, the Soviet quagmire in Afghanistan may have encouraged some of the USSR’s allies and satellites (Hungary, Poland) to assert greater independence. Last but not least: following the US withdrawal from Vietnam, there was increased concern about how committed to its Asian treaty allies the United States was going to be in light of the Nixon doctrine. None of these reputational losses was likely decisive, but they further weakened the three powers’ geopolitical position.
It is of course possible to argue that all three powers committed an avoidable mistake. The simplest explanation attributes failed strategic choices to outright but avoidable (as opposed to unavoidable due to uncertainty) miscalculation or to domestic politics (e.g. Alcibiades vs Nicias). Cognitive biases may be to blame (esp. status quo bias and sunk cost effect). For the US, the loss of North Vietnam and for the USSR the loss of Afghanistan would have represented a change to the status quo. There is a tendency to take outsized risks in defence of the status quo. All three had intervened to maintain the status quo and alliance cohesion before (e.g. US in Chile, Indonesia, the USSR in Hungary and Czechoslovakia, Athens in Melos). Subsequently, as the American and Soviet (and Athenian) interventions began to go badly, the so-called sunk cost effect led all three to double down, leading to an unnecessary prolongation of the conflicts. These biases may have distorted the strategic cost-benefit analysis.
Decision-makers may also have felt - justifiably or not - that they had little or no choice but to intervene. This is less applicable in the case of Athens, which really launched a war of choice. At the systemic level, classic power politics, balance-of-power considerations and concerns about sphere of influence maintenance offer plausible explanations of state motivation and a readiness to accept outsized risks. The security dilemma postulates that one side trying to enhance its power (and security) under conditions of anarchy diminishes the other side’s power (and security). Under condition of bipolarity, this dilemma is exacerbated, as one state’s loss exactly matches the other state’s gain, without gains/ losses being diluted/ diverted to third parties (Gilpin 1981, Deutsche & Singer 1964). Competition is also fiercer under bipolarity, as “passing the buck” is not an option. Incidentally, this is why multipolarity is generally seen as more prone to causing armed conflict than bipolarity (Waltz 1964, Mearsheimer 2001).
Another intriguing rationalisation of the interventions is to understand them as signalling devices. International politics is not solely based on material factors and brute force alone. At the very least, states need to mobilise resources to gain material power and they have to be willing to use it. The perceived willingness of a state to use its power is closely tied to non-material factors like credibility, prestige and reputation. Foreign interventions can therefore also be regarded as costly ways to signal commitment and willingness to incur costs in the defence of interest and/ or allies. Being prepared to incur net losses may in fact enhance a state’s reputation and prestige. Naturally, this is only a practical approach if the adversary also incurs significant costs, Otherwise present or future adversaries would simply exploit the intervening power indefinitely and repeatedly. Given that the cost of US support for the Afghan resistance and Sino-Soviet support for North Vietnam represented a substantially lesser cost than to the USSR and the US, respectively, signalling might work. Inevitable defeat may also only provide at best limited assurance to present allies. Relatedly, In spite of their immense power and undoubted status in the international hierarchy, states may intend interventions to set an example (pour encourager les autres), thus potentially reducing future enforcement costs (e.g. Melos, Iraq 2003?).
In other words, non-intervention may be systemically difficult and reputationally problematic. Systemically, states worry about what the local loss may do to the global balance of power. Reputationally, states are concerned about being perceived as weak and worry about further exploitation by present or future adversaries, while dodging a fight might undermine alliance cohesion and morale. States also have an incentive to send what are in fact "costly" signals in the hope of convincing the adversary that they are willing to “pay any price, bear any burden”. As suggested above, this can be a risky and ultimately self-defeating strategy. But it can work. Defending a costly geostrategic position may be rational, as rational as the gazelle that that leaps straight up in the air to signal the tiger that it is not concerned about its presence. Such a decision risks lacking credibility, but cost-benefit calculus on either side is intrinsically subjective and ambiguity may lead state to adopt such a risky strategy. Point being, it is possible – how plausible can be debated – that the decision in favour of potentially risky interventions were made with concerns about credibility, reputation and prestige in mind.
Last but not least, one should not underestimate the sense of vulnerability that tends to drive even very powerful states into risky overseas military (ad)ventures. Even superpowers feel vulnerable due to systemic competition, especially so under condition of bipolarity. Cognitively, decision-makers are also more likely to be concerned about the downside than the upside in view of a prospective loss (prospect theory). This will lead them to take riskier decisions defending the status quo than what would have been warranted after a more careful, balanced analysis. This is less applicable to Athens's decision to launch the Sicilian expedition. It does apply in the case of Vietnam and Afghanistan. (Worth remembering that the US had already "lost" China.) It may at first seem counter-intuitive that superpowers are driven to risky foreign military intervention out of a sense of weakness and vulnerability rather than strength and insatiable territorial expansion. But this is what happens, at least occasionally (Vietnam, Afghanistan vs Sicily). States should carefully consider the risks of foreign intervention and not let a sense vulnerability dictate decisions. States seeking to counter an adversary's foreign intervention should seek to understand what motivates a state's foreign intervention. Whether a state intervenes overseas out of a sense of vulnerability or out of a sense of strength should inform decisions how to respond the intervention.