Who should Tony be cosying up to?

Before and after. Betwixt and between. Old and new... However dissimilar in content and tone, these volumes share titles that characterise the current moment as a turning point. For Andrew Gamble, this cusp is marked by British intercontinental indecision; for Phyllis Bennis and David Harvey, by American unilateral assertion. In practice, Bennis' "after" fails to comprise a radical departure from "before", while Harvey's "new imperialism" resembles the old, and Gamble's diagnosis of British debilitation denotes a long-standing sclerosis. But if the authors retreat from asserting a definitive watershed, they nevertheless construe our turbulent times as a crisis of transitionality, susceptible to markedly different resolutions.

With geopolitical sands shifting underfoot, it is hard to avoid intimations of profound systemic upheaval. But the sensation of living through a pivotal phase has generated much perplexity as to why US imperialism has taken a newly territorial turn in Afghanistan and Iraq, and why Britain has chosen to stand alone as the most ardent accomplice in this endeavour. As Harvey notes in the first of his February 2003 Clarendon lectures that comprise The New Imperialism : "The evidence suggests that there is something deep at work in this. But it is hard to see what it is."

It remains so after reading Bennis. Written for the outraged but not overly informed general reader (imagined as belonging to an American "we"), Before and After devotes a chapter to the pre-history of US engagement in the Middle East since 1945, followed by a narrative account of the "war on terror" as it unfolded between September 2001 and spring 2003. As truncated chronicle of this unfinished "war without end", it is neither scholarly enough to comprise a serious contribution to the intellectual enterprise of explaining what "deep thing" underlies these events, nor current enough to satisfy seekers after a "first rough draft" of a history whose most compelling chapters are still unfolding.

Bennis fails to offer a persuasive framework for making sense of America's record of double standards and double dealings in the Middle East. Other than Bush, the devil of her piece is "unilateralism, in all its virulence".

Yet the strident tone sits awkwardly with the author's fundamentally liberal assumptions. Having identified the immediate roots of rage against the US (its uncritical support for Israel; its alignment with the Gulf's most repressive regimes in pursuit of access to the region's singular asset; sanctions against Iraq; and a dismissive repudiation of multilateralism), Bennis implies that America's egregious failings might be rather easily reversed given more clear-sighted leadership. At root, the US' global wrongs appear little deeper than a failure to commit more of its gross domestic product to international aid, and a disregard for the human rights shibboleth that Washington insistently mouths but so signally fails to respect.

Nowhere is this interpretative flimsiness more apparent than in the book's conclusion. Here, Bennis offers a wish-fulfilment version of what the president might have said, standing in the Twin Towers' smouldering rubble on September 11 2001: "Even as we continue the task of... burying the dead, we begin with the recognition that we were wrong in the past to reject the International Criminal Court... We know that such a court will be used evenhandedly - for we must unite in opposing all terrorists, not just some - Henry Kissinger may be next in the dock with the perpetrators of these latest attacks, and maybe Generals Sharon and Pinochet will be next up."

Even Americans favouring T-shirts that proclaim "Bartlett is My President" might doubt whether, in the parallel universe of the US television political drama The West Wing, their beloved leader would rush to proffer Kissinger as sacrificial lamb to the consecrating fires of Ground Zero.

Reading Harvey and Gamble requires less suspension of disbelief. Both are concerned with questions of "imperial overlap". Gamble's tour d'horizon is organised around the unravelling of England's two imperial projects, which together constitute the "English question" at the core of Britain's political crisis. The first such aggrandising project consolidated "Great Britain" as cover and vehicle for the expansionist designs of "greater England", thereby enabling the construction of vast empires of informal commerce and formal colonies overseas. But the right's vision of an empowering Commonwealth and the left's aspiration towards a redistributive commonwealth lack credibility in a postcolonial, post-Communist world, leaving a precariously united kingdom to untie - under disintegrative pressures of nationalism from within, and supranationalism from beyond.

Gamble positions British politics at the intersection of four circles: the British Union, the European Union, Empire and Anglo-America. Westminster's dilemma lies in placing Britain centrally in one circumference: Europe's orbit or America's. The inability of Britain's "political class" to make a decisive adjudication between dissolving a portion of sovereignty into the European federalist scheme or hitching the UK's waning imperial star to Washington's waxing world-ordering ambitions constitutes Gamble's central problematic. If England suffers a form of bipolar disorder in a unipolar world, his preferred prescription is clear. That the UK forms a "bridge" between the US and the EU, as Tony Blair once mooted, seems improbable given pressures for exclusive commitments. For Gamble, decisive Europeanism seems the more sagacious option: resolving Britain's disarticulation in a greater federal scheme, while enhancing Europe's potential as counterpoise to US power.

Harvey also raises questions of regional alignments and hegemonic eclipses -through the lens of "historical-geographical materialism". Here, "imperial overlap" relates to the analytic complexity of locating US imperialism within a wider account of the "empire of capital": a dynamic but diffuse phenomenon scarcely reducible to the machinations of Washington alone.

Borrowing from Giovanni Arrighi, Harvey defines "capitalist imperialism" as "a contradictory fusion of 'the politics of state and empire'I and the 'molecular processes of capital accumulation in space and time'". In teasing apart the contending logics of territorially based statecraft and unbounded capital accumulation, he makes an important theoretical contribution to understanding contemporary empire's vicissitudes. Indeed, the book would reward reading for its trenchant account of "accumulation by dispossession" alone. Lest the "postmodern" empire of neo-liberal governance appear too disembodied in its deterritorialisation, Harvey details the massive transfer of resources from South to North effected through International Monetary Fund-mandated "structural adjustment" - leaving destroyed livelihoods and punctured economies in the wake of finance capital's uncontrolled asset-stripping.

He is equally alert to the US government's increasingly desperate, militarised attempts to maximise its own favourable "asymmetries in exchange". For Harvey, Bush's blunt search for "full spectrum dominance" is born neither of overweening arrogance nor vengeful wrath against al-Qaida's sponsors. Rather, aggressive unilateralism marks a response to the US's vulnerability to systemic supercession by states and regions where capital's accumulative logic is most intensely operative. Having carefully constructed pillars in East Asia and western Europe to undergird its preferred postwar order, the US now confronts erstwhile junior partners with the capacity to constrain its perpetuation of lucrative asymmetries.

If the decline and fall of hegemons is a world-systemic inevitability, Harvey nevertheless avoids an overdetermined or fatalistic reading of Washington's recent actions. America's predicament has been aggravated by its elite's chronic inability to apportion the fruits of international accumulation to its own domestic dispossessed. Instead, Washington has let "fictitious capital" flourish, sanctioned corporate corruption on a massive scale, and failed to invest in America's own, desperately needed, infrastructural regeneration. The war on terror, in Harvey's view, thus functions as a smokescreen to distract from the gravity of America's own ungovernability, simultaneously serving as cover for Washington's "extreme makeover" of the Middle East - designed to ensure US hegemony for the next half century. But the alchemical process by which oil is transformed into the elixir of imperial potency is itself susceptible to depletion. The crisis might turn in two directions: either a form of "structural adjustment" in the US on a scale unknown since the Depression or a "return to a more benevolent 'New Deal' imperialism". Much will depend, Harvey concludes, on "regime change" in the US itself.

Susan Carruthers is associate professor of history, Rutgers University, New Jersey, US.