An unnecessary constitutional crisis in Washington

US President Donald Trump declared a national emergency last Friday, bypassing Congress as he tries to divert money from federal government funds to pay for his long-promised wall along the border with Mexico.

The president's push for US$5.7 billion in border wall funding led to a five-week government shutdown, the longest in American history, and his declaration of national emergency is bound to draw Washington into long and costly legal and political battles that will draw attention and resources from the real challenges facing the United States. US Congress has delegated emergency powers to the president so he/she would be able to act swiftly in response to a genuine national security threat - which was how Mr Trump described the conditions along the US border with Mexico. "We're talking about an invasion of our country," he warned, referring to the flow of illegal immigrants and drugs into the United States.

But at another point during his media conference on Friday, Mr Trump seemed to suggest that the declaration wasn't necessary. "I could do the wall over a longer period of time. I did not need to do this, but I'd rather do it much faster," he said.