If the point is to help Mexico battle corruption and be a more effective partner in the fight against drugs, the policy choice is clear. Emphasize the need to strengthen Mexico's corruption-riddled legal structures, but don't tweak Mexico City so mercilessly that the old nationalist anti-US button is pushed and relations slip backward.
The path chosen by the House of Representatives last week tends in the latter direction. Its rejection of President Clinton's decision to recertify Mexico as cooperative in antidrug efforts also carries the possibility of economic sanctions against Mexico.
The Senate votes this week, and that chamber would be well advised to take the more reasonable route of avoiding any implication of sanctions.
Neither Mexico nor the US wants reversal of relations. Economic ties have never been closer. Immigration remains a towering issue. The US has a tremendous stake in encouraging political reform in Mexico and not enlivening regressive statist and nationalistic elements there. Even the usually mild Mexican president, Ernesto Zedillo, jumped to the defense of Mexican sovereignty following congressional outbursts last week.
No one, however, can fault the criticism that Mexico has deep-set problems. The recent exposure of its chief antidrug official as corrupt has now been joined by a US civil judgment in Houston upholding the seizure of millions of dollars allegedly paid another former top Mexican law enforcement official, Mario Ruiz Massieu, by traffickers.
In truth, the greatest threat to Mexico's sovereignty is from graft-sowing drug lords. There, the threat from drugs is the destruction of a functioning system of law; in the US, it's the undermining of social order in city neighborhoods and the wider damage to individual morality.
When Clinton visits Mexico next month he should drive home the shared interest in fighting drugs. The US and Mexico have every reason to be close partners and friends - able to offer warranted criticism. The yearly drug certification process is just a very awkward, lopsided way of delivering it.