It is noteworthy that these failed deals do not even include ChemChina's planned $44 bn acquisition of Syngenta, which would be the largest overseas acquisition by a Chinese group. ChemChina has failed to offer concessions to a European Union competition inquiry ahead of a deadline, though both companies insist that they remain fully committed to the transaction and are confident it will go ahead.

Most of the foiled Chinese acquisitions are ostensibly because of competition or security concerns, but each of them has come amid a growing chorus of protectionism in Western countries.

Economic difficulties at home have made it difficult for policymakers in these countries to sell the merits of globalization propelled by trade and cross-border investment. But they should resist discriminating against Chinese investors; backpedaling on opening-up to Chinese investments will not help economic growth.

For Chinese companies and policymakers, the increasing scrutiny by Western regulators should not only be deemed as an unwelcome brake on the surge in Chinese takeovers. It may have unfairly disrupted some Chinese companies' legitimate plans for overseas expansion. But tightening regulatory reviews should also serve as a timely warning on the sustainability of China's overseas investments.

The current speed is faster than such optimistic predictions as China's overseas investments will grow 10 percent a year and exceed $2 trillion by 2020.

Both Chinese companies and policymakers cannot afford to ignore the high risks associated with overseas investments. Investment records indicate that many Chinese investments abroad have failed since 2005, mainly because of a lack of overseas investment experience.

An overall review of the rising tide of Chinese outbound investment is badly needed to avoid paying a too dear price for learning risk management.

The author is a senior writer with China Daily.

zhuqiwen@chinadaily.com.cn