The American midterm elections have delivered a resounding political rebuke to President Donald Trump, with Democrats wresting control of both the House of Representatives and the Senate. The outcome represents a dramatic reversal of Republican fortunes and raises questions about the direction of American politics during the remaining two years of Trump's presidency.

For Bangladesh, the implications extend well beyond the political fortunes of the White House. The elections could influence Washington's approach to trade, regional security, democracy, human rights and its increasingly complicated relationship with China. Yet Dhaka would be mistaken to interpret the Democratic victory as heralding an immediate return to the foreign policy conventions of previous administrations.

The significance of the results lies principally in the emergence of a more assertive congressional counterweight to the president. Democrats will have greater authority over legislative priorities, spending, investigations and oversight of the administration. They will also be able to scrutinise diplomatic appointments and challenge aspects of Trump's foreign policy. But he retains considerable executive authority over diplomacy and military operations. Without the two-thirds majorities necessary to override presidential vetoes, Democrats will find it difficult to reverse policies that Trump is determined to defend. The consequences of the elections will therefore be felt more through increased scrutiny, political friction and uncertainty than through an immediate reorientation of American foreign policy.

South Asia occupies a strategically important position in the competition between the United States and China. India, Bangladesh, Pakistan, Sri Lanka and Nepal all face varying degrees of pressure to balance economic interests, security considerations and diplomatic autonomy. The consequences of the Iran war are also being felt throughout the region, through disrupted energy supplies, higher import costs and mounting economic uncertainty.

The elections have placed the future of the conflict at the centre of American political debate. Rising fuel prices and the economic consequences of the war have contributed to voter dissatisfaction, making energy security a critical political issue for the administration. Trump now faces the uncomfortable prospect of having to pursue a conflict that has become increasingly unpopular at home.

The Democratic victory could strengthen pressure on the president to seek a diplomatic settlement. Congressional investigations, restrictions on funding and greater scrutiny of military operations could complicate the administration's ability to sustain the war indefinitely. Although the president retains considerable authority over foreign policy and military operations, the political cost of continuing the conflict has risen substantially.

The danger, however, is that electoral defeat could produce two very different responses. Trump may seek an agreement with Tehran to demonstrate diplomatic success and restore economic confidence. Alternatively, he could adopt a more aggressive posture, seeking to reassert American military credibility or force Iran into concessions, as a way to "finish what he started" before he leaves office. Perhaps the only thing that can be said for now with a degree of certainty, is that he will be leaving office in two years' time. Whatever path the president and his supporters may have sought to a third term (that the US constitution does not allow in its present form), that people like Steve Bannon had been talking about, is now firmly closed. For better or for worse.