1982

The Defense Communications Agency (DCA) and ARPA established the Transmission Control Protocol (TCP) and the Internet Protocol (IP) as the standard protocols for the ARPANET, known as TCP/IP. But the civil part of the government had some concerns about TCP/IP.
OSI Model

Fear grew, that the National Bureau of Standards would rather prefer a recently developed competing standard for connecting networks – the OSI reference model.
But the internet community, people like Cerf, Kahn and Postel who have been working on TCP/IP for many years resisted the OSI model from the start. In the beginning the reasons were the technical differences, especially the fact that OSI had a complicated and a much classified structure. In contrast to TCP/IP, the OSI concept has never been tested in real life. According to the internet community OSI was nothing but an aggregation of abstractions. However TCP/IP was already coined by the practical experience. The protocol already ran on a real existing network.
The most important and probably deciding argument against OSI and for TCP/IP, was the circumstance that the Department of Defense had already proclaimed their decision of using the protocols TCP and IP on all military computers.