A very brief primer: history of Internet and World Wide Web
Sorry, lads, I'm no historian, but I am over 30 and I'm fairly certain the Yanks did invent the Internet, or at least Arpanet, which most people consider the direct ancestor of our current Internet. Arpanet went TCP/IP on 1 January 1983; though, arguably, Arpanet began back in 1969 with the Stanford-UCLA link. Arpanet connected to Britain round 1973. The Brits began their own analogue of Arpanet, SERCnet, using X.25 (not TCP/IP). The (British) Post Office joined with two American companies to build the first transatlantic packet-switching network IPSS in 1978.
CERN began using TCP/IP round 1984. CERN helped proselytise TCP/IP tech across European networks and connected their own network to them in the late '80s. It was also at CERN that Sir Tim Berners-Lee (OM, KBE, FRS) started putting hypertext tech on TCP/IP networks (HTML, HTTP, etc). Finally, Marc Andreessen's team at the NCSA made a program called Mosaic that could graphically represent the hypertext 'web'. This lot eventually went private and begat Netscape...
And if we're talking about top-level domains, these were originally administered by the NIC at Stanford and IANA at USC for the US Dept of Defence. Eventually, the Dept of Commerce summoned into being... ICANN.
Like many modern technologies, multiple countries and people were involved in the development of the Internet and the WWW, but the US and UK (and their citizens) clearly played central roles. Redde Caesari quae sunt Caesaris.