Canal Security
Opponents:

"Panama is a very weak, unstable country, and I don't think it could protect the canal," Republican Senator Strom Thurmond said. (Source: PBS: The Mac Neil/Lehrer Report -- August 17, 1977)
"They doubted Panama's willingness and ability to guarantee the use of the canal for all at reasonable conditions in the future. These doubts were nourished by Panama's military defencelessness, its economic weakness and dependence on the canal, technical problems in the operation of the canal, the undemocratic government and frequent violations of human right...." - Hans G. Kausch, The World Today, Vol. 34, No. 11 (Nov., 1978).
"They doubted Panama's willingness and ability to guarantee the use of the canal for all at reasonable conditions in the future. These doubts were nourished by Panama's military defencelessness, its economic weakness and dependence on the canal, technical problems in the operation of the canal, the undemocratic government and frequent violations of human right...." - Hans G. Kausch, The World Today, Vol. 34, No. 11 (Nov., 1978).
Proponents:

"Defense Secretary Harold Brown indicated that the US military could not hope to protect the canal from determined saboteurs:
According to the best informed military opinion we can't defend the canal from a hostile panama. It is too vulnerable to a sack of dynamite - or to a glove in the gears.
Brown, like Carter, argued that the treaties, by giving Panama a greater interest in the canal's continued operation and providing the US with the right to take actions to protect the canal even after it was turned over to Panama, offered the best hope for the Canal's future security."
David Skidmore, Presidential studies Quarterly, Vol 23, No.3.
According to the best informed military opinion we can't defend the canal from a hostile panama. It is too vulnerable to a sack of dynamite - or to a glove in the gears.
Brown, like Carter, argued that the treaties, by giving Panama a greater interest in the canal's continued operation and providing the US with the right to take actions to protect the canal even after it was turned over to Panama, offered the best hope for the Canal's future security."
David Skidmore, Presidential studies Quarterly, Vol 23, No.3.