Microsoft gave up on building a Web Browser engine and you think a government can? Browser engines are really hard to build. They requires a lot of (very expensive) niche technical talent. Not to mention the need to keep up with the rate of Google's improvements to Chrome/Blink. We're at a point where Chrome has a 10 year head start to any other engine other than Firefox, building a general purpose new engine from scratch is basically off the table, and hard forking Chrome/Blink is also off the table (because why would you toss the ~1bn$ Google puts into chrome every year?). We're in a world of a single browser engine, no way to go back for the foreseeable future.