Why are embargoes an effective tool of foreign policy

An embargo is a political order that restricts trade with a specified country. It is imposed whenever a there is an unfavorable political or economical situation that comes in place between nations. Embargoes help define the strength of foreign policy by declaring a consequence of a critical act.

It is meant that like tapestry scientific theories often need to pull out since they are not relevant and often times the whole chain of theories may be pulled out.