On Friday, President Donald Trump said he would invoke powers under the Defense Production Act to direct manufacturers, including Ford and General Motors Co, to produce ventilators.

"Such close economic and trade ties indicate that there is no state of emergency between China and Japan in terms of international relations, and there is no reason for Japan to invoke national security exceptions to defend its export control measures," said Tu Xinquan, dean of the China Institute for WTO Studies at the University of International Business and Economics in Beijing.

Commerce Secretary Gina Raimondo said earlier that she might invoke the Defense Production Act, a Cold War-era law, to force companies to comply.

China's real estate giants may be forgiven if they invoke Tolstoy to make sense of their current situation.

Tu Xinquan, dean of the China Institute for WTO Studies at the University of International Business and Economics in Beijing, said, "China and Japan have close economic and trade ties, which indicates that there is no state of emergency between the two countries in terms of international relations, and there is no reason for Japan to invoke national security exceptions to defend its export control measures.

In case of a stock price downtrend, banks may invoke an agreement clause to either first warn the company concerned or liquidate the collateral in the open market, to cut losses.