While U.S. midterm elections don’t affect foreign policy much under normal circumstances, a possible Republican control of the Congress after the November 8 elections will add a new layer of complexity to Biden’s policies towards China, climate and Russia’s invasion of Ukraine. The Republicans are projected to gain control of the House of Representatives, while Senate majority is still in balance. If Republicans secure majority in both chambers, Biden’s headaches to fill key national security positions will get worse.

Biden has already struggled to fill crucial ambassador posts, as Republican senators have delayed or blocked nominations, with 39 out of 192 ambassador positions still vacant, including in Brazil, Russia and Saudi Arabia. The interim appointment of retired senior diplomats to those posts has degraded relations with key foreign partners.

The Biden administration, which try to keep a “competition and co-operation” approach with China, is also having a hard time from broad bipartisan consensus in Congress for a more confrontational approach to Beijing.

Washington’s relations with Beijing are already going from bad to worse, despite its need for Chinese co-operation in its climate and sanctions efforts. The Biden administration has worked with Congress to strengthen the U.S. edge in critical technologies, taking executive action last month to disrupt Chinese companies’ access to advanced semiconductor components and to force an exodus of U.S. capital and personnel from that industrial segment in China.

There is also strong bipartisan support to ramp up defense co-operation and coordination between the Pentagon and Taiwan’s defense authority and leadership. The Taiwan Relations Act of 2022 proposes Taipei to expand purchases of arms and Washington to provide more military training. Republicans are also vowing to force the White House to step up efforts to allow Taiwan to gain attributes of an independent state.

“We will gradually end all imports from Communist China until a new regime honors basic human rights and freedoms,” the House Republicans’ election manifesto says. While it sounds too ambitious, it would strengthen the view in Beijing of both U.S. political parties looking to disrupt China’s economic development. Biden’s recently released national security strategy talks about the need to outcompete China: “In the competition with the PRC, as in other arenas, it is clear that the next 10 years will be the decisive decade,” it says.

A Republican midterm victory could also upset the bipartisan consensus on strong U.S. support for Kyiv. A Republican Congress will rethink the “blank cheque” approach to aid for Ukraine, House Republican leader McCarthy says. The Biden Administration has already committed $66 billion in military and economic assistance and the White House pledge to do all it takes to reverse Russia’s invasion.