Here are the highlights from President Obama's 2015 State of the Union speech, including zingers on climate change and calls for tax reform. (Nicki DeMarco/The Washington Post)

“When we make rash decisions, reacting to the headlines instead of using our heads; when the first response to a challenge is to send in our military — then we risk getting drawn into unnecessary conflicts, and neglect the broader strategy we need for a safer, more prosperous world.”

President Obama used the State of the Union on Tuesday address to enumerate some of his top national security accomplishments, touting what he described as a measured, coolheaded approach to engaging with the world.

But his achievements on Cuba, Iran and other key issues will be sharply limited if he cannot secure a modicum of support from the Republican-controlled Congress.

The president’s plans to expand commercial and diplomatic ties with Cuba, for instance, have already come in for attack from congressional critics who believe that they strengthen Cuba’s repressive government. While officials are working to use executive powers to loosen some aspects of Cuba policy, the long-standing U.S. embargo is mandated by Congress.

Similarly, Obama is seeking to secure buy-in from skeptical lawmakers as his negotiators try to reach a deal to halt Tehran’s nuclear program by this summer. Already, some lawmakers are trying to push forward renewed sanctions on Iran. On Tuesday, Obama repeated his determination to veto new sanctions that reach his desk.

Obama also called on Congress to approve new legislation to bolster U.S. defenses against cyberattacks. The vulnerability of U.S. companies has been laid bare by a series of hacking incidents in recent months.

He faces an even greater challenge in convincing lawmakers to reverse their ban on moving prisoners out of the U.S. military detention center at Guantanamo Bay, Cuba, and into the United States, a key requirement for his goal of shuttering the prison before he leaves office.

Yet Obama has incensed some lawmakers with a flurry of recent transfers of Guantanamo detainees to third countries. Some influential lawmakers are already scrambling to legislate new rules to tighten transfer requirements.