Douglas London, a 34-year veteran of the CIA, warned that Trump is primarily focused on "celebrity" and "headlines."
King Abdullah II said that he and other regional leaders are still waiting to find out what will be in the White House proposal.
The senator said generals privately complain they "can't be won."
A poll by Ipsos for USA Today found that 55 percent of Americans believe the country is "somewhat" or "much less" safe.
A poll by Reuters and Ipsos Mori found cross-party majorities believed that a war with Iran in the near feature was "likely."
"Army Recruiting Command has received multiple calls and emails about these fake text messages and wants to ensure Americans understand these texts are false," military officials said.
Retired U.S. Ambassador John Limbert warned that President Trump had "no plan" and this could lead to a "disaster."
Ali Akbar Velayati said that the U.S. "took a foolish move" by assassinating Qassem Soleimani "and they must leave the region."
"Be cautious before going to public places," the Chinese embassy in Washington warned its citizens.
Iranian President Hassan Rouhani promised Soleimani's family that Americans will "feel the impact" of their "criminal act... for years ahead," the BBC reported.
"This is very difficult news, a harbinger of new clashes between the Americans and radical Shiites in Iraq," Russian Senator Konstantin Kosachev said Friday.
Republicans applauded Trump for his swift response after the attack on the U.S. Embassy in Baghdad, but Democrats were furious and worry the U.S. could be dragged into another Middle East war.
Senior Iranian commander Qassem Soleimani was killed in an American drone strike outside Baghdad International Airport on Thursday.
Iranian military officials, lawmakers and clerics have vowed to take revenge against the U.S. after the assassination of Quds Force commander Qassem Soleimani.
"We need to be very careful as we move forward," Representative Mark Green cautioned.
Rear Admiral Hossein Khanzadi said American military presence is undermining, rather than providing, regional security.
"I can compare 2019 with 2012, when they were beginning, organizing themselves," Major General Sirwan Barzani, a Kurdish Peshmerga commander, told the BBC.
The head cones were found in two separate graves at the archaeological site of Amarna
The International Institute for Strategic Studies said Tehran has established a regional network of some 200,000 fighters.
Iran is widely expected to make extensive use of its special operation forces and regional proxy militias in a hypothetical future war with the U.S.
"We're in trouble," Steve Schmidt said in a Monday interview. "You see America in retreat, literally."
Trump is dismantling a U.S.-led global architecture built by four generations, paid for by thousands of American lives and trillions of dollars of investment.
Sources close to the Turkish leader told BBC News that Erdogan "thoroughly rejected" the letter dated last Wednesday and chucked it in the trash.
Senior 2020 campaign adviser Lara Trump said average Americans had to "Google" who the Kurds of northern Syria even are before they could be outraged about President Donald Trump's decision to withdraw troops from the region.
"I am absolutely appalled that the United States is going to betray those Democratic forces in northern Syria," Pat Robertson said on "The 700 Club."
"By abandoning the Kurds we have sent the most dangerous signal possible – America is an unreliable ally," the Republican senator from South Carolina argued.
Between 19 and 21 people have been killed and hundreds injured as protesters clash with Iraqi security forces over calls for more job opportunities, an end to corruption and better access to social services.
Saudi Arabia has denied Iran's claims of receiving official messages from the kingdom, but once again, Iraq sought to play a role in mediating the Middle Eastern feud.
Iraq and Syria have boosted relations despite the U.S. opposing the latter's government and attempting to curb the influence of their mutual ally Iran.