That is a problem for the United States. Each President can generally set his or her own parameters that sometimes contradict those foreign relations that went before. Occasionally a President may establish a new policy direction such as Richard M. Nixon did in opening up Chinese relations, that persists for several generations. A President may be a trail breaking sled dog behind which the other dogs temporally follow. The dogsled may have no driver, or it could be a hidden groupthink.
For example G.W. Bush normalized relations with Libya, President Obama decided to support rebellion and destruction of the Libyan government, and today there is chaos of a sort in Libya.
While Presidents inherit some traditional relationships such as the Cold War or the trouble with North Korea, sometimes they choose to realistically change the criterion.
Because of the Iranian problems and the wounded pride of the embassy capture U.S. Presidents have selected adversity with Iran rather than something else. President Obama though, briefly tried to change or move toward normal relations with Iran. Some speculate that he was really born in a Muslim nation- Indonesia, and his Hawaiian birth paper was fudged by a friendly doctor there in an era when it was possible to do so. Growing up in Indonesia until age seven when he moved to Hawaii may have made him too sympathetic to Muslims and antipathetic to Christian interests as well as Jewish. So he signed a kind of treaty with Iran that President Trump has repudiated because it would let Iran have too good a chance to develop the infrastructure of nuclear weapons and missiles eventually, legally (meaning with U.S. acquiescence).
Conspiracy theorist like Alex Jones and Prison Planet have speculated about secret long-term formation of U.S. foreign policy that would accomplish the objectives of elite, hidden groups. It is more difficult to access Alex Jones video now because Facebook, YouTube and Apple Pod-casts have banned and deleted his work.
In some respects the lack of solid long-term planning is a strength because it would in theory enable more responsive U.S. leadership to create good foreign policy yet of course it doesn’t work out that way. An example is the project of ending the Cold War without nuclear holocaust. Ronald Reagan envisioned complete nuclear disarmament and did everything he could to realistically move toward that and normal relations with Russia. Gorbachev and Soviet leadership were moving toward normalization to, in stages, and Yeltsin accelerated that.
The Clinton administration working with Russia befitted the rich too far in wresting integral parts of Russia away. The Crimea and Ukraine were lost and formed the basis of a bilateral schism after the end of the Cold War to slowly build its renewal. President Trump sought to move toward more normal relations yet the Democrat Party has done everything they can to move the world toward the hair-trigger of Mutually Assured Destruction and total Cold War again. They hate Vladimir Putin. Hating Russia is a kind of new American tradition that reveals the lack of reasoning concerning what good foreign policy is, or how it should be made.
My best explanation is that a secret group of elitists do desire to annex Russia and Siberia because of its vast natural resources, so U.S. foreign policy will need to be in line with that principle. Finally then it could be said that the capital interests of global plutonomy control much yet not all of U.S. foreign policy.