Libya - Certainly a mistake, but let's take a look at why we went in. Libya was in the midst of a civil war in which Gaddafi was targeting the civilian population with both chemical and conventional munitions. The US, France, UK, Belgum, Denmark, Italy, Norway, Quatar, Spain and Canada all supported the air campaign made up of the US, UK, France, and Canada. this was combined with a naval blockade and economic sanctions.
Syria - Involved the UK, France, Italy, Germany, Denmark, Jordan, Turkey, Iraq, Canada, Australia, Saudia Arabia, the UAE, Bahrain, and the US; it was a fight against the ISIS caliphate and worked with Syrian native ground forces. Again, we were part of a multinational coalition; we were fighting with allies against a terrorist organization responsible for the torture and murder of an unknown number of people.
Somalia - We've been in Somalia since 1992, Obama increased our presence there to deal with what's left of al-Qaida and al-Shabab, which continues to pose a growing threat across the region. Somalia hadn't had a functional government since 1991, we are there to try to limit the influence of the extremist groups that would seek a foothold to form a new tribal territory with an extremist foundation.
Yemen - If you are so against this, why aren't you bothered by Trump's April 16, 2019 veto of a bill to get us out of Yemen? Yemen was in the midst of a civil war and was then attacked by Saudi Arabia and the UAE in a surprise air assault that was backed by numerous nations, including the US, UK, Bahrain, Kuwait, Oman, Quatar and France. Obama offered logistical and intelligence support in the form of targeting information, air to air refueling, and political support in the UN (despite evidence of war crimes). I have been opposed to our support for Saudi Arabia and the UAE in this since the first news of war crimes came out.
Then we have Trump joking with golf patrons about assassinating the military leader of a foreign nation just to try to avoid being held accountable for his numerous crimes. This was done without any discussion with Congress, no coalition was formed with other nations, and no warning was given to Iran to pull out of Iraq. This would be the equivalent of China destabilizing Mexico with a decade of war and occupation, then bombing Mike Pompeo when we tried to go in to stabilize the region in the power vacuum left by China. The fact that the motivation is entirely politically self-serving is what makes it worse; Trump has managed to further destablize the Middle East, alienate our allies, and damage our standing globally - all because he's scared to leave office and face prosecution.