The control that the Republicans have just won over the US Congress gives them an opportunity to influence all domestic and foreign policy decisions during the last two years of Obama's term that will end in 2016. The period is certain to bring sharper tensions than ever between the White House and Congress, which have already had a number of standoffs, one so severe that it forced government to shut down during the conflict over the federal budget. The midterm congressional elections and their consequences will also have an impact on the presidential and legislative elections in 2016 and the prospects of candidates from the two major US parties. The Republican majority over both houses raises two chief scenarios for the forthcoming relationship between the White House and Congress. The first is a generally cooperative relationship at least in areas where the two sides see more or less eye to eye. The fact that one party controls the executive and the other the legislature does not necessarily mean that the two sides have to be constantly at each other's throats. There are a number of domestic issues where the Republican Congress and the Democratic White House could come to terms. One is funding the fight against Ebola in West Africa in order to prevent its spread to the US following the emergence of two cases of Ebola infection inside the US. Another issue they could agree on is the federal budget, in order to avert a repeat of the government shutdown that happened last year. Also, both sides are keen to create more jobs at home, to repair and develop infrastructure and to open markets abroad for US products. These are certainly areas where the two sides could cooperate. The second scenario is an adversarial relationship in which the Republicans produce legislation that would be so adamantly opposed by the president that he would feel obliged to veto it. The Republicans may have a majority, but they do not have the 60 Senate seats they would need to overcome obstructive tactics led by the Democrats, or a presidential veto. Undoubtedly one of the chief issues that the Republicans would target is the healthcare law. Known as Obamacare, it was claimed by the president and his party as a historic victory for the Obama administration and for ordinary Americans, but it was fought tooth and nail by the Republicans. If the Republicans moved to overturn this law, Congress and the White House would definitely clash. The same would apply in the event of legislation on immigration, energy and tax reform, subjects on which the two sides hold sharply divergent views. The Republican controlled Congress can have a major impact on US foreign policy during the next two years. Congressional appropriations committees can tighten the purse strings, hampering the implementation of foreign policies. Important congressional committees, such as the foreign relations and armed services committees in the Senate, will be headed by Republican leaders who have constantly attacked Obama's foreign policies. These committees have the right to convene hearings on issues under their jurisdiction and to summon executive officials to testify before Congress and the general public. In this regard, relations between the White House and Congress will be facing a test very soon. Obama needs to turn to Congress to renew his mandate to wage aerial offensives against ISIL (the Islamic State in Iraq and the Levant) in Iraq. Currently he is relying on the mandate that Congress had given his predecessor, George W Bush. But now, in order to deploy an additional 1,500 troops in Iraq to train and advise Iraqi and Kurdish forces and strengthen their hand in their fight against ISIS he will first need to obtain congressional approval for a $5 billion allocation bill to fund military operations in the Middle East to counter ISIL in Iraq and Syria, of which $1.6 billion is to be earmarked for training and assisting the Iraqi army in its fight against ISIS. The Republicans have continuously criticised the Obama administration's handling of the humanitarian crisis in Syria. They charge that Obama abandoned Syria to Russia and Iran, turning it into a land fertile for terrorism and extremism that, in turn, could spread to the US. They argue that this happened because he had foregone the opportunity to intervene militarily in Syria that had been presented by Bashar Al-Assad's alleged use of chemical weapons against his people, thus traversing the “red line” that Obama had so clearly drawn. Such arguments do not necessarily mean that the Republicans will push for a war against Al-Assad's regime. They are sensitive to the numerous public opinion polls that indicate that the American people are opposed to more wars abroad. Also, the Republicans themselves are divided over the Syrian question, with hardliners, such as Senator John McCain, opposed to Obama's policies, while other Republicans, such as Senator Rand Paul, are keen to avert full US involvement in the crises of the Middle East. So the focus in Congress will be over the extent to which the US offers moral, material and military support to the “moderate opposition” that is not linked to terrorist organisations in order to strengthen its hand in its battle against Al-Assad. While the Republicans are divided over the handling of the Syrian crisis they are not when it comes to the Iranian nuclear programme. With Republican domination over Congress, we can expect a toughening in its positions on Iran. Many Republican members of Congress were harsh critics of the White House's rapprochement with Tehran and the easing of sanctions. They argue that Obama was too easy on Iran in the nuclear talks that could eventually make it possible for Iran to develop a nuclear weapon in the future that would threaten US allies in the Middle East, and primarily Israel. Republican criticism of the White House is likely to grow more vociferous following revelations in The Wall Street Journal that Obama had sent four secret letters to Iranian Supreme Guide Ayatollah Khamenei since taking office in 2009. The most recent of these messages was sent in the middle of last month, according to the WSJ report. It allegedly discussed possible cooperation between Washington and Tehran in the war against ISIL, although such cooperation would be contingent on reaching a comprehensive nuclear agreement by 24 November. The White House implicitly admitted this was true through its spokesman Josh Ernst, who said that US officials had discussed the campaign against ISIL with Iranian officials on the fringes of the international nuclear talks. Accordingly, the Republicans will oppose any US nuclear deal with Iran and any lifting of the sanctions. In like manner, with Republicans in control of Congress it is difficult to expect any progress in the Middle East peace process or any form of legislative pressure geared to compelling Israel to come to the negotiating table. The Republicans and the Israeli right are bound together by strong relations and the Republican Party has always supported Israeli policies in the region. Still, a Republican majority in Congress does not automatically close off Obama's foreign policy horizons and impede progress on crucial issues. Indeed, the opposite might be true. Republicans' focus on various domestic issues could give Obama the chance to focus on foreign issues and score a victory to crown the end of his administration and help his party in the congressional and presidential elections in 2016. This said, any success that Obama might have in achieving foreign policy breakthroughs while Republicans control the two houses of Congress will be contingent on his bringing new members into his administration. According to many strategists in the Democratic Party, the president's advisers and team members were the chief reason for the decline of his popularity, the Democrats' loss of their Senate majority and the defeat of their hopes to win back the House of Representatives. The challenge that faces Obama during his last two years in the White House is not to forge a new strategy for US foreign policy but rather enhancing his ability to carry out his strategy. The fact that the Republicans won the midterms is no guarantee that they will win again in 2016. The electoral prospects of both parties are contingent on the extent to which they can offer a strong policy agenda that remedies the issues that have stirred the popular discontent that informed the polls on 4 November. Chief among these are the public's economic concerns that have always been a prime determinant of voters' choices. Much, too, will be dependent on the parties' respective capacities to connect with their grassroots bases and encourage them to vote in the next elections. The writer is associate editor of Al-Siyassa Al-Dawliya published by Al-Ahram.