Donald Trump is likely to engage much more seriously in the Middle East after the US midterms.

Historically, the midterm elections in the US have often changed the power dynamics between the White House and the Congress, which has prompted US administrations to modify their approach to foreign affairs. In the recent past, there have been a number of such important foreign policy developments that have taken place as a result of electoral setbacks during the midterms.

In 2006, the sweeping victory of the Democrats in the congressional vote prompted the Bush administration to alter its approach in Iraq, pushing for a US troops surge and seeking to appease the Iranian regime.

Then the resurgence of the Republicans in the 2010 midterms (which won them the House of Representatives) predisposed then-President Barack Obama to back the military intervention in Libya a few months later – a decision he would later consider as “the worst mistake” of his presidency. And again, after the electoral defeat the Democrats suffered in November 2014, the Obama administration switched gear and started pursuing much more seriously a nuclear deal with Iran, which was meant to serve as the president’s lasting foreign policy legacy.

The Trump administration might go through similar policy shifts or adjustments after the November 6 vote. If the polls are accurate this time around, the Democrats are slated to win the House of Representatives by a narrow margin, while the Republicans are expected to retain their control of the Senate.

Whatever the outcome, the midterm elections are likely to have both direct and indirect consequences for the US foreign policy in general and more specifically in the Middle East.

Changes in Congress

The direct consequences have to do with the change in dynamics inside the US Congress and the relations between the executive and legislative branch.

There will be a change of guard in the Senate with the passing of armed services committee chair John McCain and the retirement of foreign relations committee chair Bob Corker, two outspoken critics of the current administration who will be succeeded by Trump loyalists Jim Inhofe and Jim Risch respectively.

However, there are still Senators Lindsey Graham, Marco Rubio, and Rand Paul (neither of whom are running for re-election in these midterms). All three have been occasionally critical of the White House and all have sway on foreign policy affairs.

If the Republicans retain control of the upper chamber (and quite likely they will), there is still no guarantee that they will not challenge Trump’s approach to the Middle East, especially when it comes to Iran and Saudi Arabia. Rubio and Graham are pressing the Trump Administration to do more on US sanctions against Iran, while Paul has been warning about the implications of exiting the Iran nuclear deal. In the aftermath of Saudi journalist Jamal Khashoggi’s murder, all three have called for harsh measures to be taken against Saudi Arabia, which Trump is reluctant to do. There have even been suggestions that the Republicans in Congress could “break” with the White House on this issue.

And of course, in the unlikely scenario that the Democrats take the Senate as well, this challenge would be that much bigger. The Democrats would be more aggressive in pressuring the Trump administration to take action against Riyadh and to revert to a more calibrated approach towards sanctions on Iran.

Moreover, if the Democrats take control of the House of Representatives, they are likely to use their oversight prerogatives to sway policy-making one way or the other. It is likely that the House will seek to press the Trump administration to halt US arms exports to Saudi Arabia and use it as a leverage to end the war in Yemen. The Trump administration’s recent call for a ceasefire in Yemen by the end of November is an attempt to pre-empt this expected development.

A Democrat-dominated House is also likely to push for cuts in the defence budget. The funding for Overseas Contingency Operations (OCO), which finances the US wars in Iraq and Syria, is expected to significantly decrease in 2019, which means

the White House will be limited in its ability to militarily deter Iranian influence in the Middle East.

Increasing focus on foreign policy

Electoral setbacks in midterm elections usually lead to a Congress that tends to disrupt the domestic affairs agenda of the White House. In this sense, the Trump administration is likely to focus more on foreign policy in the period between the midterm election and the start of the presidential campaign in mid-2019.

This is likely to push Trump to finally reveal details of the peace plan he announced for the Israeli-Palestinian conflict. While the president has talked extensively about his intentions to bring the Israelis and the Palestinians to the negotiating table, he has given almost no concrete details on what he will propose to the two sides. Re-starting talks, however, would entail challenging Israeli Prime Minister Benjamin Netanyahu to be ready to make significant compromises, something Trump has been reluctant to do so far. There might be potential frictions between the two if Trump gets serious about launching peace talks before the end of his first term.

The White House is also likely to continue exerting pressure on Iran but will most likely be criticised by conservatives in Congress for not getting tougher in implementing the sanctions and by the left for risking a potentially costly confrontation with the Iranian regime. Trump is also expected to make another attempt to re-engage with Moscow, but his efforts will most likely be thwarted by Democrats in Congress who are convinced the Kremlin intervened to help Trump win the 2016 presidential election.

Congressional opposition to any rapprochement with Russia could also foil any progress on resolving the Syrian issue and restarting peace talks between the opposition and the Assad regime. The US-backed Arab-Israeli axis against Iran might also suffer setbacks in the final two years of Trump’s presidency if pressure in Congress to take action on Saudi Arabia continues.

Beyond these direct and indirect consequences of the midterms, there are also several possible wild card developments that could take place in the weeks following the vote. Defence Secretary James Mattis might resign, which would alter the power dynamics inside the Trump administration and push it further to the right. Special Counsel Robert Mueller’s investigation could also be a game changer for the next US Congress if it found that there was enough evidence of collusion between the Trump campaign and Russia or of obstruction of justice by the president.

While we should expect the White House to get more engaged in the Middle East after the midterm election, the general character of its foreign policy in the region is expected to remain more or less the same: more tactical than strategic and more unpredictable than coherent.

The views expressed in this article are the author’s own and do not necessarily reflect Al Jazeera’s editorial stance.