Ronald Reagan used combat forces abroad. Reagan deployed Marines to serve in the Multinational Force in Lebanon in 1982; these men were killed in the Beirut Embassy bombing in 1983. Reagan also deployed combat forces to Grenada. Also in 1982, Reagan began supplying US forces to the Multinational Force and Observers mission in the Sinai. Gerald Ford was the only president in recent history to not deploy combat forces abroad.
Among other things, it called for the US to protect its interests abroad through the existence of a strong military. If they think you can successfully invade, they (other countries) are less likely to encroach on your interests abroad. Also the Reagan Doctrine called for obvious and open loyalty to allies.
Barack Obama.
at his or her discretion
The constitution of the US requires that a President must be born in the US.
its a long story
The history of the medical technology abroad can be traced to Italy. The Latin language is used because Latin is a dead language and is therefore used in nomenclature.
Theodore roosevelt
The present one
Teddy Roosevelt
Teddy Roosevelt to Panama.
President Obama
Bill Clinton