Shale gas and the revival of American power: debunking decline?

The spectre of American decline is once again animating both observers and practitioners of US foreign policy. The global financial crisis, a faltering American economy and continued costly and controversial military engagements overseas have been presented as conclusive proof that American foreign policy will soon lack the resources needed to sustain its previous international hegemony. Arguments of domestic weakness have been linked to analyses of the economic vitality of America's competitors to demonstrate a seemingly watertight case for relative decline. The inexorable rise of China has been presented from various quarters as evidence that the American era will soon be drawing to a close. Yet, such declinist arguments continue to suffer from fundamental weaknesses, overestimating the likely future strength of America's rivals while concurrently downplaying the capacity of the US to rejuvenate its economy and thus revivify its liberal universalist creed. The most interesting development in this regard has been the sudden resurgence of the US energy sector. Written off less than a decade ago as being in terminal decline, the American oil and gas industry has staged a remarkable recovery. Vast reserves of shale gas and accompanying tight oil offer the potential to aid the revival of the American economy, with some forecasts pointing to US energy self‐sufficiency within two decades. Notions of US relative decline may yet prove premature. The geopolitical impact of American energy self‐sufficiency is likely to be very significant, making an important contribution to a reversal of the US trade deficit, a revival of America's industrial base, and the possibility of a corresponding relative decline in power for conventional fossil fuel exporters.     

SEISMIC DESIGN AND ANALYSIS OF A KNEE BRACED FRAME BUILDING

A five-storey steel frame incorporating dissipative knee elements is designed using the Eurocode 8 pushover analysis method. The non-linear analysis makes use of a novel knee element model capable of accurately simulating the bending and shear behaviour observed in full-scale tests. The performance of the structure is assessed using non-linear time-history analysis. This shows that the knee elements can be designed to yield under small earthquakes or early in a strong one (maximising their energy dissipation) while still being able to withstand a large event without collapse. Knee elements thus have the potential to give excellent seismic performance in steel framed structures. The time history analysis results are compared to those obtained with the three different pushover analysis methods (Eurocode 8, FEMA 356 and ATC 40). The FEMA 356 method, which includes a more accurate representation of the structure's significant post-yield stiffness, gave the closest agreement with the time history analyses, while the Eurocode 8 method gave rather conservative results and the ATC 40 method appears non-conservative for this type of structure.     

THE USE OF SIMPLE PULSES TO ESTIMATE INELASTIC RESPONSE SPECTRA

Inelastic response spectra are estimated for elasto-plastic SDOF systems subjected to strong earthquake ground motions by applying the strength reduction factors determined for a simple pulse to the elastic response spectrum of the ground motion. This approach relies upon similarities in the strength reduction factors computed for earthquake ground motions and for short duration pulses. The accuracy of the estimated inelastic spectra obtained using 24 simple pulse waveforms is assessed in order to identify subsets of just several pulse waveforms that are suited for this purpose. Based upon the ground motions and pulses investigated, this approach appears to be equally applicable to short and long duration ground motions and those having near-fault forward directivity features.     

Special relationships in flux: Brexit and the future of the US–EU and US–UK relationships

A British exit from the EU would add to growing strains on the United States’ relations with Britain and the rest of Europe, but by itself would not lead to a breakdown in transatlantic relations due to the scale of shared ideas and interests, institutional links, international pressures and commitments by individual leaders. It would, however, add to pressures on the US that could change the direction of the transatlantic relationship. From the perspective of Washington, Britain risks becoming an awkward inbetweener, beholden more than ever before to a wider transatlantic relationship where the US and EU are navigating the challenges of an emerging multipolar world. The article outlines developments in the UK, EU, Europe and the US in order to explain what Brexit could mean for the United States’ approaches to transatlantic relations. By doing so the article moves beyond a narrow view of Brexit and transatlantic relations that focuses on the future of UK–US relations. In the conclusion we map out several ways in which US views of the transatlantic relationship could be changed.     

Talking to Hezbollah

The two studies under review, by Matthew Levitt and Lina Khatib et al., present very different pictures of Hezbollah, pictures which are not necessarily conflicting and are indeed, in many ways, complementary. Levitt focuses on the group's long record of terrorism dating back more than 30 years to the early 1980s and its violent attacks on US marines and French forces then based in Lebanon. Over that period, of course, as Lina Khatib and her co‐authors demonstrate, Hezbollah has grown in stature as a political party. Khatib and her colleagues portray a party that has deliberately sought to keep Lebanon a weak and divided country, despite the efforts of the West and Gulf Arab states to strengthen the Lebanese state. These two studies add immensely to our knowledge of Hezbollah and its extraordinary rise over the past three decades to become one of the major political and military actors in the Middle East.     

The Geography of the Anthropocene in New Zealand: Differential River Catchment Response to Human Impact

New Zealand provides a useful environment to test the notion that the Anthropocene is a new geological epoch. There are two well‐dated anthropogenic impact ‘events’: Polynesian settlement c. AD 1280, and European colonisation c. AD 1800. Little attention, however, has been given to regional catchment response to these, although it has been assumed that both Polynesian and European farming and land use management practices significantly increased erosion rates across most of New Zealand. This paper addresses the nature and timing of human impacts on river systems using meta‐analysis of a recently compiled nationwide database of radiocarbon‐dated fluvial deposits. This shows highly variable human impacts on erosion and sedimentation in river systems, which are often difficult to separate from naturally driven river activity. Catchment‐scale data with high resolution dating control record clearer evidence of human disturbance. In Northland, anthropogenic alluviation is recorded from c. AD 1300 linked to early Polynesian settlement, enhanced further in the late 19th and 20th centuries by European land clearance, when sedimentation rates exceeded 25 mm year^?1. This study demonstrates significant geographical variability in the timing of human impact on river dynamics in New Zealand, despite two synchronous phases of human settlement, and highlights the difficulty of formally designating a simple and single ‘Anthropocene Epoch/Age’.     

Constructing Water Shortages on a Huge River: The Case of Shanghai

Shanghai is located on the world's third largest river (by volume). Yet it faces the risk of shortages of drinking water. Many decisions and environmental characteristics have contributed to this threat. First, Shanghai has become dependent on water brought into the municipality by rivers. Second, it has become increasingly reliant on water from the Changjiang (Yangzi River), principally in order to control the levels of pollution in the water that enters its treatment plants. Third, for reasons associated with inter‐provincial administrative arrangements, the city's water intakes are located within the municipality, within the estuary zone and subject to tidal intrusions of salt water. Fourth, at high tide and when the Changjiang's discharge is low, salt intrudes far into the estuary, beyond the current water intakes. If sea levels rise, these intrusions will become more pronounced. Fifth, large‐scale central government infrastructure projects (such as dams and the South‐North Transfer) are altering the hydrological characteristics of the river. Such projects raise the probability of salt water intrusions into the water intake zone. The Shanghai and central governments have thus made a series of decisions that, taken together, have led the municipality to rely on a source of drinking water that is increasingly unreliable and subject to the risk of shortages due to salt water intrusions. Why these decisions have been made – independently – is an important problem for those who would understand the provision of water for cities and the practical efficacy of Chinese governance systems.