Dozens of young Vietnamese women lined up for hours last month to catch a glimpse of "cool" troops marching through Hanoi in a huge military parade. But it was not their own soldiers they were looking out for. It was the Chinese contingent.

The scene reflects a shift in attitudes towards China — amid trade tensions with the United States — which has allowed Vietnamese leaders to push forward with sensitive projects, such as high-speed rail links and special economic zones close to China, that may significantly boost bilateral ties.

Only a few years ago, with many Vietnamese wary of a powerful neighbor with which they have fought multiple wars, such projects were seen as too controversial and caused violent protests.