The conversation in the race for president, a month before the first ballot is cast, continued to be about national security and America’s foreign policy approach.

On Monday, Republican presidential candidates Marco Rubio and Chris Christie pitched their argument as to my they are best suited to serve as commander-in-chief.

Speaking at the American Legion in Hooksett, New Hampshire Monday morning, Rubio took aim at Hillary Clinton and some of his Republican rivals “who have voted with Barack Obama and Harry Reid rather than with our men and women in uniform” and “are apparently more passionate about weakening our military and intelligence capabilities than about destroying our enemies.”

Rubio listed off the a sampling of the threats “Barack Obama will leave to our next president,” such as China and Russia undergoing its largest military expansion in decades, the threat of ISIS, and an emboldened Iran “governed by a radical Shia cleric who’s about to receive tens of billions of dollars of sanctions relief from our president — tens of billions of dollars that will be used to sponsor anti-American, anti-Israeli terrorism and to develop long range missiles that can be used to launch nuclear weapons.”

The Republican presidential hopeful went on to argue that out of all candidates running he’s the only candidates that has a record of judgement in foreseeing world events and warning about the looming threats before they take place, whereas the remaining candidates in both parties cling to the “same plan of weakness and retreat.”

Without mentioning names, Rubio targeted Donald Trump, Rand Paul and Ted Cruz by order. “Words and political stunts cannot ensure our security. ISIS cannot be filibustered,” said Rubio. “While some claim they would destroy ISIS, that they would make the sands of the Middle East “glow in the dark,” my question is: with what? Because they certainly can’t do it with the oldest and smallest Air Force in the history of this country, or with the smallest Army we’ve had since World War II. Yet these are what we will have thanks to the cuts these candidates have supported and even tried to deepen.”

“If ISIS had lobbyists in Washington, they would have spent millions to support the anti-Intelligence law that was just passed with the help of some Republicans now running for president,” he added in a dig at Paul and Cruz.

“Our next president needs to be someone prepared on day one to execute his duty – someone with the judgment and the vision to lead this country back. I will be that president,” Rubio promised.

New Jersey Governor Chris Christie put forth his plan on “restoring American leadership” in a speech at Saint Anslem College in Manchester, NH. “A failure by our party this year, failure due to division in our party or inexperience in our nominee, would signal a deeper political crisis, as millions of Americans would conclude that the system no longer works,” Christie warned. “History is not kind to the incompetent, and it is unrealistic to expect that this dismal record of failure can go on, year after year, without severe consequences for all of us.”

Christie pitched himself as a grown up to tackle the challenges in “the most dangerous, perilous times in our country’s recent history.” He also took a dig at Trump and the two junior Senators running for the Republican nomination. “We are not electing an entertainer-in-chief. Showmanship is fun but it is not the kind of leadership that will change America,” he said. “If we are going to turn our frustration and anger with the D.C. insiders, the politicians of yesterday and the carnival barkers of today into something that actually changes American lives, we must elect someone who has been tested. Someone with proven experience. Someone who knows how to make decisions… Someone who has been held responsible and accountable for decisions, not someone who just changes the next vote if the last one just didn’t work out.”

But the insurgent Republican presidential hopeful also warned of a split within the GOP if the one of the 13 candidates are not chosen. “Splitting this party, and handing the election to Hillary Clinton, will not make America stronger, will not restore sound thinking to our foreign policy, and will not protect American lives,” he stressed. “Only by working together, within the Republican Party, can we avoid the type of weak and dangerous foreign policy we experienced with Hillary Clinton as Secretary of State. We cannot permit her to get within 10 miles of the Oval Office.”

On Sunday, Democratic presidential front-runner Hillary Clinton mocked the Republicans for having a “particular fixation on blaming President Obama and me for everything that happens in the world.” The GOP’s foreign policy consists of sending “American troops anywhere at any time to do something and, while you’re at it, bomb something – preferably carpet bomb, whatever that means. Or, don’t do anything,” according to Clinton.