MUFON is currently the largest and oldest UFO organization in the world that publishes a monthly journal, holds an annual symposium, has a structured field investigator training program and currently has more than 800 trained field investigators, has a nationwide rapid response team for high value investigations, has a membership of 2,800 people, has a continually improving computerized UFO case management system, has a trained underwater dive team, and has an active business board of directors.
That's because the people at the very top know that UFOs are real and they want to make sure that they are somewhat prepared. However I believe any alien ship land on Earth they will believe we are being attacked and respond accordingly.
Most of the beliefs the skeptics I've known are almost always ego-based. Even when they start to see your side, they will fight to be right, and no amount of proof will ever be good enough. Eventually they'll be too much evidence about UFOs for the skeptics to ignore.