Matthew 24:15-16 takes place after the gospel has be spread through the whole world unto all the nations as a witness. We ourselves are witnesses to all of the nation of the world.
The abomination of desolation in Daniel 12 is time of the end.
4 But thou, O Daniel, shut up the words, and seal the book, even to the time of the end: many shall run to and fro, and knowledge shall be increased.
there are a million theories on how this or that will go down but no one considers the day of Lord in their theories. nor does anyone theorizing consider that much of revelations may have already come to pass even though historical events match the discerptions. also it seems you're not familiar with who Magog is or the land that is Magog's and his people. most scholars have come to the conclusion that gog/magog is the Russian people.
also the bible is written by the Jews to the Jews for the Jews unless specified otherwise hence prophecy is written from the prospective of Jerusalem the land called Israel and the Jewish people. for example, the worst time Jews have experienced in their history is the holocaust which officially started the day of broken glass in 1938 to 1945 the end of the European war. coincidentally is 7 years and a great tribulation of the Jewish people.
the day of the Lord as promised by the two that remained when Jesus ascended at the Mt of Olives that He would return there, of which also confirms OT prophecy of the Mt of Olives becoming a valley and the sun and the moon are obscured by dust no doubt. you might not know that it is well known or believed to be true that there is a nuke arsenal under the Mt of Olives. and when the Mt blows, rest assured that the world will respond in like kind. and no one will know what happened until its over because computers are running the show on that. no bureaucracy can confirm and deploy before they are being fried. so computers flying in the sky, a sky net if you will, is the only way to respond to incoming missals.