Last month, U.S. President Barack Obama cited national security concerns in blocking Chinese company Ralls Corp. from buying four wind farms in northern Oregon. Obama’s Republican challenger, Mitt Romney, says that if elected, he would label China as a currency manipulator on his first day in office. Last week a U.S. congressional committee labeled two major Chinese companies national security threats and urged the Committee on Foreign Investment in the United States (CFIUS) to block any attempt by them to acquire U.S. companies.

As U.S. politicians from both major political parties increasingly take a get-tough attitude toward China, American law firms trying to do business there are feeling caught in the middle.