改进非凸估计与非对称时空正则化的红外小目标检测方法

针对复杂背景下的红外小目标检测,在非对称时空正则化约束的非凸张量低秩估计算法基础上,提出了一种新的核范数估计方法代替原算法中的估计方法。提出基于结构张量与多结构元顶帽(Top-Hat)滤波的自适应权重张量对目标张量进行约束,增强目标张量稀疏性的同时抑制其中残存的强边缘结构。实验结果表明,所提改进算法能够更好地消除图像中强边缘结构对检测结果的影响,在保证检测率的情况下,较原算法具有更低的虚警率。     

India’s nuclear counter-revolution: nuclear learning and the future of deterrence

ABSTRACT

The India–Pakistan near war of February–March 2019 highlights India’s ongoing evolution in strategic thought and practice since its emergence in 1998 as an overt nuclear-weapon possessor. These changes, involving an increasing willingness to engage in the intentional escalation of conflict with a nuclear-armed rival willing to be the first to use nuclear weapons, challenge certain academic assumptions about the behavior of nuclear-weapon states. In particular, they undermine the expectations of the nuclear-revolution theory—which anticipates nuclear and conventional restraint among nuclear-armed rivals through fear of mutual assured destruction—and the model of nuclear learning which underpins this theory, in which new nuclear-weapon states gradually absorb this restraint through policy-maker learning. This article explores how India’s learning pathway since 1998 has deviated from these expectations. India is instead pursuing its own “revolution,” in the direction of creating capabilities for flexible response and escalation dominance. It concludes by illuminating the similarities between Indian strategic behavior and contemporary practices of other nuclear-armed states, and suggests that New Delhi’s emerging de facto nuclear doctrine and posture is part of a broader empirical challenge to our current conceptions of the nuclear revolution and of nuclear learning.     

Remembering and forgetting Mirambo: Histories of war in modern Africa

ABSTRACT

While the study of organised violence is considered essential to understanding the history of the West, and accordingly imbued with various layers of meaning and remembrance, war is widely regarded as inimical to the modern nation in Africa and stable development more broadly. Using examples drawn from primarily from East Africa, this paper considers the ways in which warfare in the deeper (‘precolonial’) past has been framed and envisioned in recent decades, in particular by governments whose own roots lie in revolutionary armed struggle and who began life as guerrilla movements. While in some cases particular elements of the deeper past were indeed mobilised in pursuit of contemporary political goals, in many other scenarios histories of precolonial violence were beheld as problematic and unworthy of remembrance. This paper highlights the paradox and ambiguity which has attended the memory of key aspects of Africa’s deeper past.     

Pakistan’s nuclear future: continued dependence on asymmetric escalation

ABSTRACT

In 2019, the geostrategic landscape of South Asia significantly changed. A crisis between India and Pakistan involved air strikes across international boundaries for the first time since the 1971 war. Pakistan came close to economic collapse, while India re-elected hawkish Narendra Modi as prime minister in a landslide. These developments, alongside the United States’ efforts to strike a deal to leave Afghanistan and rapidly improving US-India relations, portend new challenges for Pakistan’s security managers—challenges that nuclear weapons are ill-suited to address. Despite the shifting security and political situation in the region, however, Pakistan’s nuclear posture and doctrine seem unlikely to change. This article explores the roots of Pakistan’s reliance on the traditional predictions of the nuclear revolution, most notably the notion that nuclear-armed states will not go to war with one another, and argues that this reliance on nuclear deterrence is a response both to Pakistan’s security environment and to serious constraints on moving away from nuclear weapons toward an improved conventional force posture. Pakistan’s central problems remain the same as when it first contemplated nuclear weapons: the threat from India, the absence of true allies, a weak state and a weaker economy, and few friends in the international system. While 2019 may have been a turning point for other states in the region, Pakistan is likely to stay the course.     

India’s emerging space assets and nuclear-weapons capabilities

ABSTRACT

Over the last five decades, India’s nuclear and space programs have gone through several phases, from collaboration to divorce to supportive. An interplay of two factors determined the nature of the relationship. One was the state of India’s nuclear-weapon program. The second was international conditions, especially India’s relationship with the nuclear-nonproliferation regime. In the early decades, because of the rudimentary nature of India’s nuclear and space programs, the relationship was collaborative, since the rocket technology being developed was a necessary adjunct to the nuclear-weapon program. Subsequently, as India’s rocketry capabilities and nuclear-weapon program began to mature and concerns about international sanctions under the non-proliferation regime began to grow, the two programs were separated. The Indian rocketry program was also divided, with the civilian-space and ballistic-missile programs clearly demarcated. After India declared itself a nuclear-weapon state in 1998 and the programs matured, the relationship has become more supportive. As the two programs mature further, this relationship is likely to deepen, as the nuclear-weapon program requires space assets to build a robust and survivable nuclear deterrent force.     

Cyber-weapons in nuclear counter-proliferation

ABSTRACT

Under what conditions are cyber-weapons effective in nuclear counter-proliferation? With continued interest in nuclear proliferation professed by Iran, North Korea, and Saudi Arabia, a discussion of the effectiveness of counter-proliferation measures remains relevant. Cyber-attacks as military option in a state-on-state conflict still requires additional corroborating evidence to make conclusions about its long-term effectiveness. This work analyses the general applicability of cyber-weapons and their usefulness in nuclear counter-proliferation. Through a comparative case study of Operation Orchard, Stuxnet, and recent “Left-of-Launch” operations against North Korea, the essay finds that cyber-operations are not particularly effective against nuclear programmes that are in the later stages of their development. They can disrupt and delay a nuclear programme temporarily, if the attack remains clandestine, but cannot halt nuclear proliferation all together. However, effectiveness increases if they are used in combination with conventional weapons. The article addresses a topic of interest to national-level decision-makers: whether cyber-operations can and should play a role in nuclear counter-proliferation.     

Memory,magic and militias: Cora Indian participation in Mexico’s wars,from the reforma to the revolution (1854-1920)

ABSTRACT

Mexico’s Cora Indians have played an outsized role in national history, thanks to their skilful use of guerrilla tactics and success in forging strategic alliances with outside forces in defence of their cultural, territorial and political autonomy. Cora participation in elite struggles between Liberals and Conservatives (1850–73), and subsequently in the Mexican Revolution (1910–20), helped to shape the way that both conflicts played out in Western Mexico. Such participation also allowed Cora communities to keep hold of traditional landholdings in the face of political and economic reform, while sowing the seeds for the foundation of the Mexican state of Nayarit.     

Chinese views of the nuclear endgame in North Korea

ABSTRACT

This article examines Chinese views of North Korea’s nuclear-weapon program during the Donald J. Trump administration. It shows that China has portrayed itself as a responsible country that promotes regional stability, unlike the United States, which has engaged in military brinkmanship with North Korea. Some Chinese foreign-policy experts have asserted that Beijing should back Pyongyang in the event of war because of their shared history of humiliation by great powers, while others have favored working with other regional partners. Another theme in Chinese discourse about North Korea is that Pyongyang is an impetuous, ungrateful regime that impedes Beijing’s ability to attain its core interests of regional stability, economic development, and heightened global influence. This negative assessment of North Korea drove Beijing’s endorsement of stricter UN sanctions in 2017. While Beijing has punished Pyongyang for its wayward policies, China responded favorably to North Korea’s decision in April 2018 to stop nuclear tests and partake in international dialogue. Beijing seeks to help Pyongyang gradually disarm and develop its economy within a Chinese-led East Asian order. The article concludes by explaining how Beijing’s recent, more positive view of Pyongyang is likely to affect its support for American efforts to dismantle North Korea’s nuclear-weapon program.