If Vietnam has over the last year symbolised Southeast Asia's re-engagement with the United States as a hedge against China's rise, then it also represents the limits of that trend.
While Hanoi might feel comfortable with the long-term symbolism of an emerging strategic partnership with Washington, not to mention the prospect of regular US warship visits for rest and repair, it is worth repeating that a more formal security pact the US and its allies is hardly on the cards.
Whether it is with Washington, Beijing or beyond, Hanoi's envoys repeatedly stress what is effectively a 'three no's' policy at the heart of a determinedly internationalist approach born of grim decades of war and isolation as a pariah state. That policy means no foreign military bases in Vietnam, no use of Vietnamese soil to attack another nation and no joining of a military alliance.
It's a reminder that while Hanoi may want diverse relations with a balance of international powers, it does not want to be bullied or beholden to any single power - again, a symbol of a wider feeling in parts of Southeast Asia.
Can the Vietnamese pull it off? The tensions of recent months, as the long-simmering disputes with China over the South China Sea dominate the region, show just how fraught that exercise can be.
As they cautiously feel their way with their one-time bitter foes in Washington, question marks emerge on both sides.
The Pentagon fears a Vietnamese cockiness that could lead to unnecessary provocation of China on the high seas and unwittingly inflame wider tensions. In Hanoi, meanwhile, they wonder whether the US can really be trusted. Are they really around for the long term? Or will they find an excuse to back off in favour of the more important and complex Sino-US relationship?
