With Brazil behind him and Colombia and Central America ahead, it must already be abundantly clear to Ronald Reagan just how dependent Latin America is on the United States.
At the same time, he cannot have missed the very evident strains in US-Latin ties - both in the economic and political spheres.
President Joao Baptista de Oliveira Figueiredo minced no words in outlining the problems. He complained of growing protectionist tendencies in the US. Brazil and the other developing countries, he also said, ''suffer the most with the contraction of world trade, the obstruction of international financial flows , and the worldwide economic recession.''
Left unspoken, but not far from the surface in the talks here, was the specific concern about the effect of the US economic recession on Brazil. ''We feel every twist and turn in the US economy,'' said a Brazilian Economy Ministry official. ''In fact, those twists are magnified here.''
Mr. Reagan tried to take the sting out of such criticism by frequently referring to Brazil and the US as partners needing to work together to solve trade disputes.
''The leading developing nations,'' he said in a speech in Sao Paulo, ''should all enter the world trading system as full partners.'' He obviously had Brazil in mind and hoped that this message would get across.
The US, moreover, is aware that Brazil - which faces a massive $85 billion foreign debt, much of it owed to US private banks - must expand its trade to keep itself solvent.
The fact that President Reagan was here, spending two working days in long meetings with President Figueiredo, however, encourages Brazilians. They also view a $1.2 billion US loan to Brazil, announced Wednesday, as a vote of confidence that Brazil can overcome its economic problems. They would agree with a Foreign Ministry spokesman who said, ''The visit puts us in the forefront of US thinking.''
But Brazilians temper their enthusiasm with realism. They know that President Reagan faces a variety of issues that could nudge Brazil into the background.
''That must not happen,'' President Figueiredo is quoted as saying following one of his meetings with Mr. Reagan. ''I don't believe it will.''
To protect against such an eventuality, the two nations are setting up a group of ministerial commissions to tackle issues from trade to nuclear policy, from debt problems to military strategy, during the coming years.
Secretary of State George Shultz and Brazilian Foreign Minister Ramiro Saraiva Guerreiro will be choosing members of these working groups.
Economic issues - particularly the debt and trade - were the key issues discussed.
Brazilians are pleased over the recent ruling of the US International Trade Commission that sidelined a request by the Fairchild-Swearingen Corporation for duties against Brazil's state-subsidized Bandeirante commuter aircraft, which is making inroads into the US air commuter market at the expense of Fairchild's Metro II.
But there are plenty of similar complaints by US firms about Brazilian imports that will require smoothing out by the working groups.
Both countries indicate they want to resume military cooperation, which came to a grinding halt in 1977 when Brazil unilaterally abrogated a 30-year-old agreement out of pique at President Jimmy Carter's frequent criticism of the Brazilian military government's human-rights record.
It appears unlikely at this writing that the presidents would actually set in motion a new military accord, but the working group on military matters will probably be charged with drafting one.
On the inter-American system, there was solid agreement between the presidents that the system is needed, and must be preserved and strengthened. Brazilians assured the Reagan team that, in Brazil's view, the Argentine-British war over the Falkland Islands did not put undue strains on the system. They told the US delegation they believed that US support for Britain in the conflict was understandable.
Moreover, Brazilian officials privately said that they were surprised by the recent US votes in the United Nations and in the Organization of American States in support of resolutions calling on Argentina and Britain to begin negotiations on the future of the islands.