BEIJING, March 24-- The Untied States has seemingly outgrown its childish paranoia against the Asian Infrastructure Investment Bank (AIIB), but the encouraging development should not be allowed to go to the other extreme: a Machiavellian plot.

Signals have been beamed out of Washington of late that it is adopting a cooperative attitude toward the China-proposed initiative, which marks an apparent change of mind from its earlier suspicion and obstruction.

The U-turn of the world's sole superpower, which has developed an almost instinctive repulsion for whatever it images might turn into a threat to its hegemony, is overdue but still welcome, and also indicative of the attractiveness and all-win nature of the incipient institution.

But Washington needs to keep its AIIB epiphany pure and clean, and resist the temptation to load it with a Machiavellian ploy to convert the fledgling project into yet another tool for exerting its influence and getting its own way.

The AIIB is born out of and aimed at satisfying the huge demand for infrastructure investment in fast-growing Asia, a sum that has skyrocketed way out of the capacity of established regional and global lenders.

That means its creation will not only help break the infrastructure bottleneck and boost regional development, but almost certainly bring considerable returns to any party participating in or cooperating with the enterprise.

Thus the AIIB amounts to a new cornerstone to the foundation of the existing financial architecture, further underpinning instead of undermining the system, just as the Asian Development Bank and similar regional bodies have strengthened -- rather than weakened -- global lending and world development.

Another aspect of the AIIB's magnetism is that, as Beijing has insisted in chorus with other participants and aspirants, the AIIB will function as an open and inclusive organization dedicated cooperation and development, not as an arena to wield power and influence.

Given Washington's record on international affairs and preoccupation with dominance, the U.S. about-face has given rise to speculations that the superpower, since unable to scuttle the AIIB, now attempts to keep the China-initiated financial body on its own orbit by engaging with it.

Such theory, although easy to understand, is not necessarily true, but it is the United States that bears the onus to clear the air by making a convincing case that it does not have a hidden agenda.

And Washington had better to have waken up with a change of heart, not merely a change of tactic. For the AIIB members will not allow their urgently needed and highly promising project to be reduced to a chessboard of geopolitical game.