Shares of Lockheed Martin (LMT) - Get Report were lower in early afternoon trading on Monday, as it was the latest company to come under fire from a tweet by President-elect Donald Trump. "The F-35 program and cost is out of control," Trump tweeted. "Billions of dollars can and will be saved on military (and other) purchases after January 20th."

CEO's need to accept that this is how things will be going forward and they need to plan accordingly, former Marco Rubio Communications director and senior advisor Alex Conant said on CNBC's "Squawk on the Street" on Monday morning.

"This is the new reality for American businesses," he claimed. "And they need to accept the reality that Donald Trump is going to wake up in the morning and more often than not, fire off a tweet about an American company. And it has real-world ramifications as we're seeing with Lockheed today. Their stock price down almost 5%."

Conant listed three steps companies can take to protect themselves in this new reality.

First, companies need to "assess their own risk" and then prepare tweets ahead of time that could be used to answer critical tweets.

Second, they should "establish back channels" with Trump's administration to talk with them and ensure that everything is on the table and there are no misunderstandings, Conant advised.

Third, each company needs to be monitoring the TV because Trump will sometimes telegraph his tweets or say something against a company during an interview.

Trump's power will probably not wear off no matter how many times he criticizes individual companies in tweets because he has the "loudest mouthpiece in the entire world," Conant said. "That's the power of the White House is essentially the bully pulpit."

(Lockheed Martin is a holding in David Peltier's Dividend Stock Advisor.)