The Pentagon is reducing its counterterrorism forces in Africa and studying whether to make similar moves elsewhere in the world as part of a broad effort to shift American military focus toward what it calls threats from Russia and China.The planned 10% cut from US Africa Command's total force of 7 200 troops will be carried out over several years, the Pentagon said in a brief statement. It said the reductions will not touch military operations in Libya, Somalia or Djibouti. They will be focused on countries in west Africa; the Pentagon did not cite any specific countries as examples, but the US has relatively small military groups operating in Nigeria, Niger, Cameroon and elsewhere.In Africa, as in other parts of the world where extremist groups pose threats, the US military's approach has been to provide training and other forms of support for local armies so that they can do the main fighting against extremists. Even so, US forces have suffered casualties in Africa, including in Niger in October 2017 when four US soldiers and four of their Nigerien partners were killed in an ambush that sparked a fierce firefight with more than 100 insurgents.Africa Command is the first US regional military command to begin implementing reductions in counterterrorism forces, but others in Europe, the Pacific and elsewhere will be weighing the possibility of cuts. This is in line with Defence Secretary Jim Mattis's desire to focus more on potential conflict with Russia and China, and less on the insurgent wars of the past 17 years. This was spelled out in a revised national defense strategy published in January.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and FacebookThe defense strategy is based on the Trump administration's belief that the central challenge to US security and prosperity is what it calls the re-emergence of strategic competition with China and Russia. While threats from extremist groups like the Islamic State in Syria and Iraq are deemed significant, they are no longer the main US defence focus."It is increasingly clear that China and Russia want to shape a world consistent with their authoritarian model — gaining veto authority over other nations' economic, diplomatic, and security decisions," the defense strategy said.The strategy document described China as a strategic competitor using "predatory economics" to intimidate its neighbors while militarising areas in the South China Sea. It asserted that Russia has violated the borders of nearby nations, including Ukraine, and "pursues veto power" over the economic, diplomatic, and security decisions of its neighbors.This has convinced Mattis that the US must accelerate its efforts to maintain a dominant position in space while doing more to prepare combat troops for war on a far larger scale than they have faced in Iraq and Afghanistan. It also is at the core of the Pentagon's rationale for investing hundreds of billions of dollars to modernize the nuclear weapons arsenal.